Eurycyphon Watts, 2011

Zwick, Peter, 2015, Australian Marsh Beetles (Coleoptera: Scirtidae). 8. The new genera Cygnocyphon, Eximiocyphon, Paracyphon, Leptocyphon, Tectocyphon, and additions to Contacyphon de Gozis, Nanocyphon Zwick and Eurycyphon Watts, Zootaxa 3981 (4), pp. 451-490 : 465-466

Genus Eurycyphon Watts, 2011

Type species: Eurycyphon fulvus Watts, 2011

The habitus characters separating Eurycyphon from Cyphon (in the old sense; part) and Pseudomicrocara in the generic key ( Watts 2011) remain valid after the discovery of additional species of Eurycyphon and after dismantling the heterogenous group of „Cyphon-like“ species. All species I presently include in Eurycyphon agree between them, and are excluded from other non-saltatorial genera, by:

• broadly oval domed body, pronotum narrower than the elytra and narrowing anteriorly, the front angles are blunt and project barely or not at all;

• side of elytron behind the humerus explanate for a short distance; • the wide grooved elytral epipleuron.

The general description ( Watts 2011) did not address cephalic sutures. A line extending forward from the straight parallel gular sutures and the subgenal ridge join. Together they meet the edge of the head capsule where the maxilla is inserted. From about this point an oblique low ridge runs across the wide but shallow antennal furrow and meets the eye. Prosternal process drop-shaped, receiving mesoventral groove short, wide, U- or widely Vshaped. Mesoventral process fully developed, sides parallel, caudally finely incised. Discrimen visible over most of mesoventrite. Abdominal sternites unmodified, last somewhat pointed.

Males share the following: T8 distally densely covered with microtrichia and some interspersed socketed setae of similar size. No fringe of long setae along the regularly rounded caudal edge (e.g., Fig. 43 , 57 ). A pair of fine struts delimiting a bare pale window may extend back from the arched connection between the strong short apodemes. S8 is large, V- or broadly U-shaped, with some setae on the caudal remnants of the plate ( Figs. 45 , 58 ). The bare T9 resembles T8 with regard to the basal windows and the paramedian fine struts extending back from the connection between the apodemes. However, the fine struts may reach very far back and include between them a median area forming a caudal lappet extending further back than the rest of the plate ( Fig. 44 ). S9 is large, with paired sclerites whose anterior ends approach but do not meet. Caudally there are numerous large socketed setae ( Fig. 46 ). The male genitalia include a short stylus (e.g., Figs. 41 , 49 ).

An exceptionally long pala in combination with a short trigonium and short outwardly curved parameroids with dorsally displaced bases are apomorphic character expressions supporting the monophyly of a group comprising the type species, E. fulvus , and species in couplets 6–9 of the key. A network of resemblances in the terminalia connects them, they are most easily identified by comparison of the illustrations.

A conical projection on ventrite 5 of females of E. aquilus Watts and E. fulvus Watts was a proposed diagnostic character of Eurycyphon ( Watts 2011) . However, the female of E. perlatus n. sp. and of Eurycyphon sp. A lack this structure. Other females are unknown.

Tectocyphon is also broadly oval but rather flat. Its pronotum lacks front angles, covering the head completely from above ( Figs. 21–23 ). The male genitalia of Tectocyphon follow a uniform pattern with anteriorly weak or divided pala which is never the case in Eurycyphon . The multiple porous fields on female sternites may be a generic character of Tectocyphon but too few females are known to confirm this.

Figures

FIGURES 41 – 48. Eurycyphon spp., males, I. E. fulvus Watts: 41, ventral view of S 9 (part), tegmen and penis; 42, the same, apical portion of penis and tegmen, enlarged. E. barringtoni, n. sp.: 43, T 8; 44, T 9; 45, S 8; 46, S 9; 47, ventral view of tegmen and penis; 48, the same, apical portion, enlarged. 43 – 46 to the same scale. pa, pala; pd, parameroid; pe, paramere; st, stylus; tr, trigonium.

FIGURES 52 – 60. Eurycyphon spp., males, III. E. falcatus, n. sp.: 52, ventral view of tegmen and penis; 53, 54, apex of penis in ventral and lateral views, enlarged; 55, apex of tegmen and parameres enlarged; left half of figure in ventral, right half in dorsal view. E. tricornis, n. sp.: 56, antenna; 57, T 8; 58 S 8; 59, tegmen and parameres; 60, penis in dorsal view. 53 – 55, 57 – 58, and 59 – 60 to the same scales, respectively. pd, parameroid; pe, paramere; st, stylus; tr, trigonium.

FIGURES 49 – 51. Eurycyphon spp., males, II. E. thunguttii, n. sp.: 49, ventral view of tegmen and penis; 50, the same, apical portion, enlarged. E. aquilus Watts: 51, apical portion of tegmen and penis. pa, pala; pd, parameroid; pe, paramere; st, stylus; tr, trigonium.

FIGURES 21 – 26. Tectocyphon microphallus, n. gen., n. sp., male. 21 – 23, habitus; 24, head, ventral, labium and maxilla removed; 25, labium; 26, maxilla. 25, 26 to the same, 21 – 23 not to scale. ep, epipleura; es, episternum; gs, gular suture; sg, subgenal ridge.