Cochlostoma crassilabrum ( Dupuy, 1849 )

Gofas, Serge, 2001, The systematics of Pyrenean and Cantabrian Cochlostoma (Gastropoda, Cyclophoroidea) revisited, Journal of Natural History 35 (9), pp. 1277-1369 : 1292-1294

Cochlostoma crassilabrum ( Dupuy, 1849)

(®gures 10±13)

Pomatias crassilabrum Dupuy, 1849 : no. 275Ð1851: 511, pl. 26 ®gure 11. Type locality:` Lourdes , BagneÁres , Navarrens’ , French western Pyrenees. Syntypes, 22 shells, coll. H. Fischer ex Dupuy, MNHN.

Pomatias crassilabris [Stabile ms.] Saint-Simon, 1867b: 5 (unjusti®ed emendation).

Pomatias mabillianus Saint-Simon, 1869: 7 ±8. Type locality: Eaux-Bonnes , valley between the spa and Pic de Ger. Five syntypes in coll. Locard ex Saint-Simon, MNHN. Possible syntypes in coll. Bourguignat, MHNG .

Pomatias frossardi Bourguignat in Frossard, 1870: 18. Type locality: Aurensan cave near BagneÁres de Bigorre.

Pomatias spelaeus Fagot, 1876: 62 . Type locality: lower level of BeÂdat cave near BagneÁres de Bigorre.

Pomatias hidalgoi var. laburdensis de Folin and BeÂrillon, 1877: 202 ±203. Type locality: Sare, Cambo, Hendaye (PyreÂneÂes Atlantiques). Cochlostoma (Obscurella) laburdense (de Folin and BeÂrillon) : Kobelt, 1902: 502.

Pomatias berilloni Fagot, 1880b: 300 (unneeded replacement name for P. laburdensis , introduced in synonymy). Pomatias berilloni Fagot : Fagot 1891: 293.

Pomatias fagoti Bourguignat in Fagot, 1880c: 29 ±30 (of reprint), pl. 1 ®gure 5. Type locality: Ars waterfall near Aulus (ArieÁge). Possible syntypes: two shells labelled` Aulus’ in coll. Bourguignat, MHNG.

Pomatias ventricosus SalvanÄaÂ, 1887: 141. Type locality: Navarran Pyrenees.

Pomatias harlei Fagot, 1888: 198 (nomen nudum)Ð Guipuzcoa.

Pomatias isoicus Fagot, 1889: 11 (in reprint). Type locality: between Ochagavia and Iso, Navarra. Syntypes: two shells labelled` Iso’ in coll. Bourguignat ex Fagot, MHNG.

Pomatias isabanus Fagot, 1889: 11 ±12 (in reprint). Type locality: near Isaba, valley of Ezca river , Navarra. Syntypes: two shells labelled` Isaba’ in coll. Bourguignat ex Fagot, MHNG.

Pomatias W licium Fagot, 1889: 12 (in reprint). Type locality: below Larrau pass, valley of the Anduria between the pass and Ochagavia , Navarra .

Pomatias bearnicus (Bourguignat ms.) Fagot, 1891: 293 (135 in reprint). Type locality: valley of Eaux-Chaudes.

Pomatias saulcyi (Bourguignat ms.) Fagot, 1891: 293 (135 in reprint). Type locality: near the cave of Eaux-Chaudes, PyreÂneÂes Atlantiques. Syntypes: six shells reg. no. 160916/ 6 in coll. Jetschin ex Fagot, SMF .

Pomatias daralli (Bourguignat ms.) Locard, 1894: 344. Type locality: valley of Pic de Gave , near Eaux-Bonnes .

Pomatias angustus (Bourguignat ms.) Locard, 1894: 345. Type locality: Eaux-Chaudes. Syntype: one shell, coll. Locard, MNHN .

? Pomatias (Rhabdotakra) obscurus var. jetschini Wagner, 1897: 586 , pl. 3 ®gure 29. Type locality: Gerde, Hautes-PyreÂneÂes. Lectotype ( Zilch, 1958: 60), reg. No. 159927, coll. Kobelt, SMF; paralectotypes, reg. no. 159928/9 and 159929/1, coll. MoÈllendorOE, SMF.

Pomatias (Rhabdotakra) berilloni var. kobelti Wagner, 1897: 588 , pl. 3 ®gure 34. Type locality (restricted by lectotype designation): Bilbao, Vizcaya. Lectotype ( Zilch, 1958: 58), reg. No. 160056, coll. Kobelt, SMF; paralectotypes, reg. No. 160057/10 and 160058/17 (Bilbao), coll. Kobelt, SMF; reg. no. 160061/9 and 160062/8 (OrdunÄa), coll. Kobelt, SMF; reg. no. 160059/4 (Bilbao), coll. MoÈllendorOE, SMF; reg. no. 160060/1 (Bilbao), coll. Jetschin, SMF.

Description

Shell up to 13.5 Ö 5.5 mm with 7 to 8.5 quite rounded whorls. Early whorls with a peripheral angle which is totally concealed by the suture; body whorl slightly constricted, rounded. Sculpture very weak, wrinkled, on the ®rst embryonic half whorl, then with very ®ne axial ribs on the following one and one half whorls. Spire whorls with quite strong and irregular ribs (8±9 ribs/mm) on fourth and ®fth whorls, then with ribs becoming graduall y more crowded (up to 12±13 ribs/mm); no terminal thickening of ribs along the suture.

Aperture thickened and expanded into a collar, without a distinct rim inside. Peristome quite distinctly auriculated, gradually narrowing and slightly deēcted inwards at the columellar insertion, not distinctly auriculated at the parietal insertion.

Shell colour tawny, with a series of brown subsutural blotches, an interrupted suprasutural brown band continued on the periphery of the body whorl, and a narrow, continued peri-umbilical brown band. Whitish intervals between brown blotches formed by pale segments of the ribs. Peristome white.

Female and male genital systems as in general description.

Geographic range and variation

The populations assigned to C. crassilabrum occupy the largest range of all species considered herein, in the Pyrenees and eastern part of the Cantabrian range.

The montane populations in the Pyrenees are distinguished morphologically from the lowland ones assigned to C. obscurum in having a taller outline, with a more de®nitely constricted body whorl. The outer lip of adult shells is thicker, more brightly white, and more distinctly auriculated at the columellar end. The distinction at the species level of foothill (assigned to C. obscurum ) and montane ( C. crassilabrum ) Pyrenean populations is based on the genetic distances which range between 0.32 and 0.42 and on the existence of alternative ®xed alleles at the ODH locus (®gure 13; see remarks under C. obscurum ).

In the area of Eaux-Bonnes, central Pyrenees, some individuals are distinguished by a lighter shell colour and a very narrow peri-umbilical band (®gure 10d). This form was named Pomatias mabillianus Saint-Simon, 1869 , and accepted as a valid species by Germain (1931) and more recently (but without a discussion) by Marcuzzi and Biondi (1980). The electrophoretic data do not support that they are anything but individual variants in the local population of C. crassilabrum .

To the west of the Pyrenees, there is a cline towards the small-sized, coarsely sculptured populations of the Basque country (®gure 10g,h). In these populations, the post-larval spire whorls are darker, and the ribs there may be as few as seven to eight/ mm. The transition to this morphology is gradual, and no clear-cut geographical limit can be set to delimit subspecies. I could not ®nd either any clearcut allozymic diOEerentiation between montane Pyrenean and western Basque populations, which all share the`slow’ ODH alleles as a distinctive trait. The most obvious diOEerence is the absence of LDH B in Basque populations (®gure 13).

The earliest available species-group name for the Basque populations is laburdensis (de Folin and BeÂrillon, 1877) , introduced as a variety of C. hidalgoi and later raised to speci®c status by Kobelt (1902: 502). Pomatias berilloni Fagot 1880 is an unnecessary replacement name which was used several times ( Locard, 1894: 348; Germain, 1931: 578 ±79); the name laburdensis (based on the Basque province of Labourd) is not a homonym of lapurdensis Fagot, 1880 (based on latinized name of Lourdes) (articles 57f and 58 of ICZN). Records of C. nouleti from the Basque country (e.g. Locard, 1894) are based on misidenti®ed specimens of this coarsely ribbed form.

A very peculiar morphology can be seen on specimens found in nineteenth century collections originating from Gerde (near BagneÁres-de-Bigorre, Hautes- PyreÂneÂes). These are distinguished from surrounding populations by a lower, more compact spire, thin ribbing, and paler shell colour. This form was distinguished as var. jetschini by Wagner (1897) and raised to subspeci®c rank by Zilch (1958); it was independently recognized as a species by Locard (manuscript name Pomatias gerdei in Locard collection). I attempted to ®nd this morph, but all specimens from this area in my material have the normal morphology of C. crassilabrum .

Habitat

Among limestone, with a preference for shaded surfaces on loose mounds of large blocks. In the French Pyrenees, C. crassilabrum is mostly found on exposed limestone surfaces, whereas populations on the southern slope (provinces of Huesca and Navarra) are typically found on mounds of limestone blocks in shaded places. In the Basque provinces further west, the usual habitat is the base of limestone surfaces, under the shelter of the grass lying against the rock.