Gyrinus ovatus Klug, 1829

Fery, Hans & Hájek, Jiří, 2021, Nomenclatural and taxonomic notes on some species of Gyrinidae (Coleoptera), Acta Entomologica Musei Nationalis Pragae 61 (1), pp. 55-71 : 62-69

Gyrinus ovatus Klug, 1829

( Figs 4–6 , 9 , 12–13, 15 )

Gyrinus ovatus Klug, 1829: 3 (original description; type locality: ‘Süd -Brasilien’).

Gyrinus gibbus Aubé, 1838b: 709 (original description; type locality ‘Brésil’); RඣǤංආൻൺඋඍ (1883b):186 (redescription);RඣǤංආൻൺඋඍ (1903): 74 (new records); OർIJඌ (1924): 230 (redescription); syn. nov.

Gyrinus (Neogyrinus) gibbus : OർIJඌ (1935): 128 (subgeneric association, redescription); OർIJඌ (1949): 277 (redescription); OർIJඌ (1954): 132 (redescription); Cඈඅඉൺඇං et al. (2014): 188 (distribution, literature); Gඎඌඍൺൿඌඈඇ & SIJඈඋඍ (2017): 484 (redescription, Venezuela).

Gyrinus apicalis Sharp, 1878: 117 (original description; type locality: ‘Santa Cruz’ [ Brazil]); RඣǤංආൻൺඋඍ (1883b): 186 (synonymy with G. gibbus ); syn. nov.

Type material. Gyrinus ovatus: The syntype series of G. ovatus Klug found in the MNBG consists of five specimens arranged in a single row. The first syntype in this row is the best preserved male and we designate it hereby as lectotype of Gyrinus ovatus Klug, 1829 ( Fig. 4 ): Lൾർඍඈඍඒඉൾ: J, ‘10340’ [printed], ‘Sello. l.’ [green, handwriting unknown; text most probably meaning ‘Sellow leg.’], ‘ovatus N.’ [handwriting Klug: the ‘N.’ means ‘new’], ‘ Gyrinus gibbus Aubé , det. Ochs 1937’ [handwriting Ochs], ‘Hist. Coll. ( Coleoptera ), Nr. 10340, Gyrinus ovatus N., Brasil Sellow, Zool. Mus. Berlin’ [green, printed], ‘ Lectotype, Gyrinus ovatus KඅඎǤ, 1829, Fery & Hájek des. 2020’ [red, printed] (see Fig. 4a ). Pൺඋൺ- අൾർඍඈඍඒඉൾඌ:2 JJ 2♀♀, ‘10340’ [handwriting],‘Hist. Coll.( Coleoptera ), Nr. 10340, Gyrinus ovatus N., Brasil Sellow, Zool. Mus. Berlin’ [green, printed]; one male with additional ‘ovatus? Brasil.’ [handwriting Ochs] ( MNBG).All four paralectotypes are provided with a respective red label. Originally, all specimens were pinned, but are now glued on cards; the original pins have been kept.

Gyrinus gibbus: According to the text in Aඎൻඣ (1838b), the author has studied more than a single specimen. In the collection Oberthür ( MNHN) exists one specimen which can be reliably identified as one of the syntypes and which we designate hereby as the lectotype of G. gibbus Aubé, 1838 ( Fig. 6 ): Lൾർඍඈඍඒඉൾ: J, ‘gibbus. Aubé., ovatus var. m [= mihi],. in Brasil. merid.’ [green, hw Dejean], ‘Ex Musaeo, Dejean’ [printed], ‘Muséum Paris, 1952, coll. R. Oberthür’ [printed], ‘Type’ [red, printed], ‘Syntype’ [red, printed], ‘ Syntype, Gyrinus , gibbus Aubé, 1838 ’ [printed], ‘ MNHN, EC 9691’ [printed], ‘ Lectotype, Gyrinus gibbus Aubé, 1838 , Fery & Hájek des.2020’ [red, printed], ‘ Gyrinus ovatus Klug, 1829 , Fery & Hájek det., 2020’ [printed] (see Fig. 6a ). It is noteworthy that on the first label the specific name ‘ gibbus ’ with author Aubé is given. Thus, we must assume that Dejean made this label after publication of Aඎൻඣ’s ‘Species général’ (1838b). The words ‘ovatus var. m[ihi]’ may be a hint on the statement in Aඇඈඇඒආඈඎඌ (1839: 88) that the material in Dejean’s collection was mixed up (see above).

Gyrinus apicalis: The syntypes of G. apicalis Sharp, 1878 are stored in the IRSN. We designate hereby one male of these syntypes as lectotype ( Fig. 5 ): Lൾർඍඈඍඒඉൾ: J, ‘St. Cruz, C. v. Volxem, det. Sharp’ [black margin, hw Severin], ‘7920’ [printed], ‘ Gyrinus apicalis, Ind. typ., D.S.’ [hw Sharp], ‘Syntype’ [printed, red on white label, with black margin], ‘Coll. R. I. Sc. N. B.’ [printed, brown label], ‘ Lectotype, Gyrinus apicalis Sharp, 1878 , Fery & Hájek des. 2020’ [red, printed], ‘ Gyrinus ovatus Klug, 1829 , Fery & Hájek det.2020’ [printed] (see Fig. 5a ). 14 additional specimens are stored in the IRSN which might belong to the original syntype series. These are all from Brazil and with collecting data as cited by SIJൺඋඉ (1878): St. Cruz, Rio Janeiro, Entre Rios and Porto Novo. We refrain, however, from declaring them paralectotypes because they are not labelled by Sharp, and and thus we are not sure if they belong in fact to the syntype series..

Additional material studied. BRAZIL: 1J, ‘Brazil,Wehncke’ ( NMPC). 1 ♀, ‘Brésil, coll. Régimb.’ [hw Severin], ‘ G. apicalis Shp’ [hw Régimbart], ‘Coll. Séverin, Détermin. Régimb. 1890’, ‘11111’; 1 ♀, ‘Brésil, coll. Régimb.’ [hw Severin], ‘Coll. Séverin, Détermin. Régimb. 1890’, ‘11114’; 1 specimen (abdomen lacking), ‘Brésil, Coll. Chevrolat, Det. Régimb. [18]82’ [hw Severin], ‘7919’. COLOMBIA: 1 ♀, ‘Colombie, Lansberge, Det. Sharp’ [hw Severin], ‘7921’. VENEZUELA: 1 J, ‘Venezuela, coll.Chevrolat, Det. Régimb. [18]82’ [hw Severin], ‘ Gyrinus semistriatus (Chv), Venezuela D. Rojas’ [hw Chevrolat], ‘7921’ [printed]; aedeagus lacking. Without locality data: 1♀, ‘Coll. Chevrolat., Det Régimb - [18]90’ [hw Severin], ‘rotundipennis, Chevr. i. litt.’ [hw Severin], ‘11114’ (all IRSN).Six further specimens from the IRSN without locality data shall not be listed in detail.

Comments. The type locality of G. ovatus Klug is ‘Süd -Brasilien’ [= southern Brazil]. The species was published in a price-list of duplicates present in the Berlin Museum and offered for sale. Nevertheless, the work contains descriptive notes on many of the taxa included and several of them are marked by an ‘n.’ as new to science. On page 3 of this work starts a list with specimens from southern Brazil and here is given: ‘ Gyrinus ovatus n. convexus, subtus testaceus, supra fusco-aeneus, elytris, dorso obsolete, punctatostriatus, apice truncatis ( G. natatore minor.)’ [= Gyrinus ovatus n. convex, venter testaceous, upper surface with blackish metallic sheen, elytra with punctures lines, obsolete on disc, apex truncate (smaller than G. natator )]. The collector of the syntype series was Friedrich Sellow (also spelt ‘Sello’), a German gardener and naturalist who travelled to Brazil and Uruguay between 1814 and 1831. For more information see HൺർκൾඍIJൺඅ (1995) and ZංඌർIJඅൾඋ et al. (2013). There is no doubt that Dejean had good relations with German entomologists and that he and Klug likewise exchanged material (see KඅඎǤ 1829: 1). We assume that Dejean had received material of G. ovatus from Klug in the early 19th century.

The type locality of G. gibbus Aubé is ‘Brésil’. In Aඎൻඣ (1838b: 709) the description of G. gibbus is given directly after the description of his G. ovatus . The texts of the descriptions are more than 90% identical, but G. gibbus was described as having the external posterolateral angles of the elytra broadly rounded while these angles are described as distinct and not rounded at all in G. ovatus Klug sensu Aඎൻඣ (1838b).

The type locality of G. apicalis SIJ ൺඋඉ is ‘Santa Cruz’ [ Brazil] and the syntypes were collected by van Volxem. Gඎඌඍൺൿඌඈඇ & SIJඈඋඍ (2017: 484) assumed that the type locality is ‘likely Santa Cruz do Sol, Brazil’ which is situated more than 1100 km SW of Rio de Janeiro. According to PඋൾඎൽIJඈආආൾ ൽൾ Bඈඋඋൾ (1886: 103), van Volxem collected in the years 1872–1873 ‘aux provinces brésiliennes de Rio Janeiro et Minas Geraes’ (and in Argentina). This is why we believe that the type locality of G. apicalis is another Santa Cruz which is located about 20 km W of Rio de Janeiro, ca. 22.93S 43.68W.

Diagnosis. We refrain from giving a complete redescription of G. ovatus Klug and refer instead to the redescriptions in Aඎൻඣ (1838b: 709; under G. gibbus ) and a very detailed redescription in Gඎඌඍൺൿඌඈඇ & SIJඈඋඍ (2017: 484; also under G. gibbus ). Nevertheless, it seems to be important to give at least some notes on the most characteristic features of the species – the apical part of the elytra and the male and female genitalia. The posterior margin of the elytra ( Figs 4–6 and 9 ) is more or less evenly curved over its entire length. Traces of a corner at the epipleural angle (where a denticle is present in G. racenisi , see Figs 7–8, 10–11 ) can be found in several specimens (sometimes a little more distinct than in Fig. 9 ), but not forming a distinct corner or a denticle. The shape of the aedeagus is given in Figs 12–13 ; the apical part of the median lobe is nearly parallel-sided in the lectotype of G. ovatus Klug ( Fig. 12 ), but it is slightly broadened in the lectotype of G. apicalis ( Fig. 13 ). The female genitalia are given in Fig. 15 . We found that the latter are somewhat variable and a reliable determination should be supported by other characters.

Distribution. Argentina, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guyana, Paraguay, Peru, Uruguay, Venezuela (Cඈඅඉൺඇං et al. 2014: 188), ‘… potentially as far as Mexico …’ (Gඎඌඍൺൿඌඈඇ & SIJඈඋඍ 2017: 489).

Gyrinus racenisi Ochs, 1953 ,

status reinstituted

( Figs 7–8, 10–11 , 14, 16 )

Gyrinus (Neogyrinus) racenisi Ochs, 1953: 188 (original description); Gඎඌඍൺൿඌඈඇ & SIJඈඋඍ (2017): 493 (in synonymy).

Gyrinus ovatus Dejean : Aඎൻé (1838b): 708 (description; ‘ Brésil et Cayenne’).

Gyrinus ovatus Aubé : RඣǤංආൻൺඋඍ (1883b): 185 (description); OർIJඌ (1924): 230 (description).

Gyrinus (Neogyrinus) ovatus Aubé : OർIJඌ (1935): 126 (subgenus association, description); OർIJඌ (1949): 276 (description); OർIJඌ (1954): 132 (description); Cඈඅඉൺඇං et al. (2014):189 (distribution, literature); Gඎඌඍൺൿඌඈඇ & SIJඈඋඍ (2017): 493 (description, Venezuela).

Type material. We were unable to study the holotype (a female) of this taxon which – according to OർIJඌ (1953) – is stored in the ‘Museo de Biologia de la Universidad Central de Venezuela’. We studied, however, one female paratype from SMF ( Fig. 7 ): ‘ ♀ ’, ‘R:42’ [printed], ‘Espino, Guàr., 29.3.[19]50, Racenis L.’ [hw?], ‘Coll. G. Ochs’ [printed], ‘Paratypoid’ [red, printed], on reverse ‘ SMF, C 9258’ [hw?], ‘racenisi Ochs’ [hw Ochs], ‘Senckenberg-Museum,Frankfurt/Main’ [printed], on reverse ‘G. racenisi’ [hw?] (see Fig. 7a ).

Additional material studied. BRAZIL: A specimen which so far was treated as a syntype of ‘ G. ovatus Aඎൻඣ’ is stored in the MNHN ( Fig. 8 ): ‘ovatus. Klug, h. [= habitat] in Brasil. merid. D. Schuppel’ [green, hw Dejean], ‘Ex Musaeo, Dejean’ [printed], ‘Muséum Paris, 1952, coll. R. Oberthür’ [printed], ‘Syntype’ [red, printed], ‘ Syntype, Gyrinus ovatus Aubé, 1838 ’ [printed], ‘ MNHN, EC 9690’ [printed]; we have added a label ‘ Gyrinus racenisi Ochs, 1953 , Fery & Hájek det. 2020’ [printed] (see Fig.8a ). 1 J, ‘J’, ‘St. Cruz, C. v. Volxem, Det.Sharp’ [hw Severin], ‘J ♀, Gyrinus ovatus Aubé, D.S. [= David Sharp], Santa Cruz. 10–17. 7. [18]72’ [hw Sharp], ‘7919’; 1 ♀, ‘ ♀ ’, ‘St. Cruz, C. v. Volxem, Det. Sharp’ [hw Severin], ‘R. Mouchamps vid., 1955, Gyrinus ovatus Aubé. ’; 2 JJ, same labels as the J above, but without Sharp’s handwritten label; 1 specimen in very bad condition, abdomen lacking, ‘Rio Janeiro, C. v. Volxem, Det. Sharp’ [hw Severin], ‘7920’, ‘R. Mouchamps det., 1955, Gyrinus ovatus Aubé’. PARAGUAY: 1J, ‘ Paraguay, Capiata, Rio Paraguay, xii-1936 ’, ‘R. Mus.Hist.Nat., Belg. I. G. 11.241’, ‘R. Mouchamps det., 1955, Gyrinus ovatus Aubé’. URUGUAY: 1 ♀, ‘ Montevideo, coll. Chevrolat, Det. Régimb[art]. [18]82’ [hw Severin], ‘ Gyrinus ovatus Aubé /°°,Dj Cat 3 p. 66 [= Dejean Catalogue 3, p. 66], Brasilia Montevideo.’ [hw Chevrolat], ‘Gyri margine-striatus Chv, Mvid [?] a....[four illegible letters]’ [hw Régimbart] (all IRSN).

Diagnosis. As for G. ovatus Klug , we refrain from giving a complete redescription of G. racenisi and refer instead to the (re)descriptions in OർIJඌ (1953: 188), Aඎൻඣ (1838b: 708; under G. ovatus ) and Gඎඌඍൺൿඌඈඇ & SIJඈඋඍ (2017: 494; under G. ovatus Aubé ). However, we believe it is necessary to give some notes and illustrations of the apical part of the elytra and the male and female genitalia which – as in G. ovatus Klug – are rather characteristic.

The posterior margin of the elytra is broadly rounded at the sutural angle, more laterally straight (or even slightly sinuate) and here forming a distinct corner at the epipleural angle sometimes with a denticle ( Fig. 10 ). This corner or denticle is in most specimens studied quite small, but in the specimen from Paraguay it is very distinct ( Fig. 11 ). The shape of the aedeagus is given in Fig. 14 ; it is conspicuously broadened apically. The female genitalia are given in Fig. 16 .

Distribution. Argentina, Bolivia, Brazil, Ecuador, French Guiana, Guatemala, Mexico, Paraguay, Peru, Uruguay, Venezuela (Cඈඅඉൺඇං et al. 2014: 189, Gඎඌඍൺൿඌඈඇ & SIJඈඋඍ 2017: 497; all under ‘ G. ovatus Aubé’).

Gyrinus bicolor Fabricius

and Gyrinus paykulli Ochs

( Figs 17–19 )

History of classification. The status of the name Gyrinus bicolor Fabricius, 1787: 194 has been disputed for a long time as has the identity of the taxon as well. The text of the original description is ‘ G [yrinus]. niger subtus ferrugineus, pedibus posticis compressis. Habitat in Sueciae aquis Prof. Leske. Maior praecedente [= G. natator ] totus supra niger, subtus ferrugineus. Pedes postice valde compressi.’ The main information contained in this description is that the specimen(s) studied have a black dorsal surface and a ferruginous ventral surface. In Fൺൻඋංർංඎඌ (1792: 202) the former text is more or less reproduced and gives no additional information.

We refrain from giving a thorough presentation of the history of the different developments and interpretations of Fabricius’ species, but reproduce ‘ Notes on synonymy ’ given by Hඈඅආൾඇ (1987: 56, 57) which contain essential historical details and interpretations (see also Bൺඅൿඈඎඋ- Bඋඈඐඇൾ 1950: 350 ff.). In particular, we believe that Holmen’s assumption that G. bicolor might be conspecific with Gyrinus urinator Illiger, 1807 should be considered accurate. ‘ Fabricius (1787) originally described G. bicolor on specimen(s) of same size as natator , with a reddish ventral side, and collected in Sweden by Leske. The type material has not since been discovered, and the identity of the species remains uncertain. The only Fennoscandian species which normally has a reddish ventral side is the small G. minutus described by Fabricius (1798). Paykull (1798) interpreted Fabricius’ description as the species now known as G. paykulli Ochs. A few years later Fabricius (1801) added to the description that the species is elongate, but this character may have been taken from Paykull’s description. Other authors have considered Fabricius’ species to be identical with G. natator (L.), G. substriatus Stph. or G. caspius Mén. All these may, like paykulli , have parts of the ventral side reddish. Anyway, both paykulli and natator are present in Fabricius’ collection, but under the name ‘ natator ’. There is also the possibility that the original specimens of bicolor were wrongly interpreted as Swedish, as Leske also worked on many Italian insects. If this is the case, the specimens might well be conspecific with G. urinator Ill. This is the European species which normally best fits the original description of bicolor , and it is very common in the Mediterranean area. Olivier (1795), Paykull (1798) and Latreille (1807) never originally described species by the name Gyrinus bicolor , as stated by many authors; each of these authors merely interpreted Fabricius’ description as one of the above mentioned species.’

We want to add that Holmen did not study the material in Fabricius’ collection, but took information in part from OർIJඌ (1927b: 37). In this work further information can be found regarding the interpretation of the taxon G. bicolor during the last centuries. Ultimately, OർIJඌ (1927b: p. 39) concluded: ‘ G. bicolor F. ist ... im Katalog als unidentifizierte Art zu vermerken.’ [= In the catalogue G. bicolor F. must be declared as an unidentified species.]. This means that G. bicolor is a nomen dubium, an opinion with which we agree. OർIJඌ (1927b) did not mean the Fabrician G. bicolor , but the species which Pൺඒκඎඅඅ (1798) interpreted as being that of Fabricius and which is often cited as ‘ Gyrinus bicolor Paykull’ (also with ‘sensu Paykull’ or ‘sensu auctores’).

Notes on the type material. In order to clear the identity of Gyrinus bicolor Fabricius , we have studied the specimens which stand in the Fabricius’ collection in a box under the joint name ‘ natator ’ (hw Fabricius). There is one male with the label ‘ natator L.’ and another male with ‘ bicolor Payk. ’ ( Fig. 17a ), both labelled by Ochs. The former is not a G. paykulli , but the latter is in fact this species ( Fig. 17 ). It lacks all abdominal ventrites including the genitalia. Fൺൻඋංർංඎඌ (1787: 194) described the ventral surface of G. bicolor as ‘subtus ferrugineus’ which means more or less ‘entirely reddish brown’. However, the ventral surface of the specimen is largely blackish; the only reddish brown aspects being the: mouthparts, gula, hypomeron, epipleura of elytra, mesoventrite shortly between procoxae, metacoxal plates near end of metaventral processes, metaventral processes distally, all legs including trochanter and pro- and mesocoxae. The ventral surface may be somewhat darkened by aging and it is quite dirty, covered in part with fungal mycelia. We have added a printed label ‘ Gyrinus paykulli Ochs, Fery det. 2020’.

All of these observations show that there is no direct evidence that either of the two specimens was studied by Fabricius or belong to what he named G. bicolor . We also sent a request to the Dublin Museum where the coll. Leske (or parts of) is stored. Unfortunately, no Gyrinidae specimens could be found and we must conclude that the syntypes of G. bicolor are lost or at least not identifiable as such. We refrain from fixing the identity of G. bicolor by designating a neotype, because no matter from which species a neotype is chosen – G. paykulli or G. urinator or even any other species – the stability of the nomenclature would be considerably threatened as the current name of each species in question would fall into synonymy with the name G. bicolor .

It is, however, necessary to designate a lectotype of Gyrinus paykulli Ochs, 1927b , for which a name bearing type has never been properly defined. The specific name is available, nevertheless, because before 2000 it was not obligatory to explicitly designate syntypes or a holotype for a newly described taxon in the original work. It is a widely accepted valid name – for instance we know more than 200 works published in the last 50 years in which it is used. On the other hand, it is considered a junior synonym of G. bicolor by F. Bൺඅൿඈඎඋ-Bඋඈඐඇൾ (1950, 1953), Fඋංൽൺඒ (1988; a widely distributed work and still in use by many entomologists), AඇǤඎඌ (1989), and Áൽගආ (1996). However, we suspect that not all authors who used the name G. bicolor meant the species which at present is called G. paykulli ; e.g. Mൺඓඓඈඅൽං (1995) considered G. bicolor either a synonym of G. minutus Fabricius, 1798 , G. caspius Ménétriés, 1832 , or G. paykulli (all with question mark).

We therefore fix the identity of G. paykulli . The normal procedure would be to designate a lectotype from among the material which Ochs used when he published the new name. However, OർIJඌ (1927b) did not explicitly indicate any material in his work. There is, however, an indirect hint at the material in his work: ‘ Ich schlage daher vor, die bisher als bicolor Payk. bezeichnete Spezies in Zukunft als G. Paykulli nom. nov. zu führen, da Paykull die erste unzweideutige Beschreibung davon gegeben hat; ...’ [= This is why I propose to classify in the future as G. Paykulli nom. nov. the species, which so far was called bicolor Payk. , because Paykull was the first to give an unambiguous description; ....].

According to Articles 72.4.1 (‘The type series of a nominal species-group taxon consists of all the specimens included by the author in the new nominal taxon (whether directly or by bibliographic reference), ...’) and Article 74.4.1.1 of the ICZN (‘For a nominal species or subspecies established before 2000, any evidence, published or unpublished, may be taken into account to determine what specimens constitute the type series.’) one might argue that formally all specimens in the collections of all authors and collectors standing under the name G. bicolor ‘Paykull’ belong to an enormous quantity of syntypes. However, we consider only those specimens as syntypes which were studied by Ochs personally. Definitely, among these syntypes are those which Ochs in the year 1927 preserved in his own collection.

The senior author has studied all 78 specimens which stand under G. paykulli in the Ochs collection (SMF). Among them, there is a series of 10 specimens from Barnaul ( Russia, Siberia). These specimens are mentioned (under ‘ G. bicolor Payk. ’) in OർIJඌ (1927a: 48). Thus, there is no doubt that Ochs had studied these specimens and that they belong to the syntype series. From these syntypes stored in the SMF we designate here the lectotype of Gyrinus paykulli Ochs and consider the other nine specimens as paralectotypes:

Lൾർඍඈඍඒඉൾ:J ( Fig. 18 ) with the following label data: ‘15 99’ [collection number?] [printed], ‘ Barnaul am Ob , leg. Babiy 17.IV.1920 ’ [printed, date hw in part], ‘coll. G. Ochs’ [printed], ‘ Senckenberg-Museum , Frankfurt / Main’ [printed], on reverse ‘R18, P7’ [hw?], ‘ Lectotype, Gyrinus paykulli Ochs, 1927 , Fery & Hájek des. 2020’ [red, printed] (see Fig. 18a ). The aedeagus ( Fig. 19 ) is glued behind the specimen, preparation most probably by Ochs. P ൺඋൺඅൾർඍඈඍඒඉൾඌ: 2 specimens with same label data except collection numbers ‘15 89’ and ‘16 03’; 4 specimens with same label data except date ‘ 27.IV.1919 ’ and printed collection numbers ‘18 31’, ‘18 32’, ‘18 34’ and ‘18 35’; 1 specimen with same label data except date ‘ 18.IV.1920 ’ and printed collection numbers ‘15 32’; 2 specimens with label data ‘ Sibirien., Barnaul a. Ob, 21.4.[19]20 Babiy’ [printed except date], ‘ G. Ochs det.’ [printed], ‘ex Coll.G. Ochs’ [printed],‘Senckenberg- Museum, Frankfurt / Main’ [printed]. All nine paralectotypes are provided with the respective red paralectotype label. Possible other paralectotypes in the collection Ochs are not labelled by us as such.

Notes on the lectotype designation of Dineutus

Figures

Figs 4–6: Habitus of Gyrinus lectotypes. 4 – Gyrinus ovatus Klug, 1829; 5 – Gyrinus apicalis Sharp, 1878; 6 – Gyrinus gibbus Aubé, 1838. 4a–6a – respective labels.

Figs 7–11: 7–8 – Gyrinus racenisi Ochs, 1953: 7 – habitus of ♀ paratype; 8 – specimen of G. ovatus sensu Aඎൻඣ (1838b) in the coll. Dejean. 7a–8a – respective labels. 9–11 – apical part of right elytron of: 9 – G. ovatus Klug, 1829 (lectotype); 10 – G. racenisi (♀ paratype); 11 – G. racenisi (Paraguay, Capiatá, Rio Paraguay).

Figs 12–16: Genitalia of Gyrinus species. 12–14 – aedeagus of: 12 – G. ovatus Klug, 1829 (lectotype); 13 – the same (lectotype of Gyrinus apicalis Sharp, 1878); 14 – Gyrinus racenisi Ochs, 1953 (Brazil, Santa Cruz). 15–16 – female genitalia of: 15 – G. ovatus Klug (paralectotype); 16 – G. racenisi (Brazil, Santa Cruz). 15a–16a – respective labels.

Figs 17–19: Gyrinus paykulli Ochs, 1927. 17 – specimen of Gyrinus ‘bicolor’ in coll. Fabricius; 18 – lectotype of Gyrinus paykulli. 17a–18a – respective labels. 19 – aedeagus (lectotype of G. paykulli).