100 CTCLOPHOKID.E. 



Original description: — "Pt. testa umbilicata, discoidea, solida, 

 superne arcnato-striatula, nitida, purpurascenti-castanea ; spira 

 plana, vertice subtili, lucide castaiieo ; sutura alba; anfr, 6 con- 

 vexis, ultimo latiore, peripheria obsolete angulata, antice descen- 

 dente et juxta suturam promiiientiatn fornicatam forniante, basi 

 violaceo; apertura diagonali, subcirculari ; perist. duplicato, 

 incrassato; interno superne suleo triangulari interrupto, externo 

 subpatente, superne producto et in prominentiam anfractus ultimi 

 abeunte. 



" Diani. maj. 25, min. 21^, alt. 8 mm." (Pfeiffer.) 



Hah. Ceylon. 



141. Pterocyclus bilabiatus, Sowerhy. 



Fterocydos bilabiatus (Sowerby), Benson, Zool. Joiirn. v, 1835, 

 p. 402 (no description) ; Pfeiffer, Zeits. Malak. iv, 1847, p. Ill ; 

 Eenaon, A. M. N. H. ser. 2, i, 1848, p. 346; Pfeiffer, Conch.- 

 Cab., Cyclostomaceen, 1849, p. 193, pi. 24, figs. 11-14, 1853, 

 p. 231 ; Gray, Nomencl. Moll. Brit. Mus. 1850, p. 13 ; Pfeiffer, 

 Zeits. Malak. viii, 1851, pp. 4, 137 ; id., Cat. Phaneropn. Brit. 

 Mus. 1852, p. 31; Adams, Gen. Eec. Moll, ii, 1855, p. 277; 

 Blanford, J. A. S. B. xxx, 1861, pp. 363, 364 ; Reeve, Concli. 

 Icon, xiv, 1863, Pterocyclos, pi. 3, tip-. 13; Hanley & Theobald, 

 Conch. Ind. 1870, pi. 5, fig. 2 ; Theobald, Cat. Shells Brit. 

 India, 1876, p. 38. 

 Cyclostoma bilabiahim, Sowerby, Thes. Conch, i, 1843, p. 110, 

 pi. 25, figs. 81, 82. 



Pterocyclus bilabiatus, Nevill, Hand List, i, 1878, p. 262 ; Kobelt 

 & Mollendorff, Xachr. Deuts. Malak. Ges. xxix, 1897, p. 113; 

 id., Cat. Pneum. 1899. p. 25 ; Kobelt, Das Tierreich, Lief. 16, 

 1902, p. 163 ; id., Conch. -Cab., Cyclophoridae, ii, 1909, 

 p. 724. 



Original description: — "Shell discoid, with a depressed, nearly 

 flat spire, of a pale colour, undulated with chestnut ; volutions 

 live, rounded, increasing gradually in size, quite smooth ; suture 

 distinct, rather deep; aperture nearly circular, witb a double 

 peritreme; inner peritreme simple, notched at the upper part, 

 outer one sinuous and undulatei-l, running into a vaulted lubercle 

 at the upper part ; umbilicus large and spreading, volutions 

 distinct Avitbin ; operculum circular, spiral, concave within, convex 

 and lamellar externall3^" (Sowerhi/.) 



Diam. maj. 20, min. 17, alt. 8 "5 mm. 



Hub. India : Salem, Madras [Heath) ; Ivolamullay Hills and 

 Nilgbiris {Blunford) ; Coonoor Pass {NeviU). 



Var. conica, Nevill. 



Pterocyclus bilabiatus, var. conica, Nevill, Hand List, i, 1878, p. 262; 

 Kobelt & xMOlleudorft", Nachr. Dents. Malak. Ges. xxix, 1897, 

 p. 113; id., Cat. Pneum. 1899, p. 25; Kobelt, Das Tierreich, 

 Lief. 16, 1902, p. 163. 



" An elevated closely wound form." {Nevill.) 

 Ilab. Ceylon. 



