112 CYCLOPHORTD^. 



1852, p. 44 ; Adams, Gen. Kec. Moll, ii, IS-^-S.p. 277 ; H. Nevill, 



Eimm. Ilelic. Pneum. Ceylon, 1871, p. 5 ; Theobald, Cat. 



Shells Brit. India, 1876, p. 38; Jousseaume, Mem. See. Zool. 



France, vii, 1894, p. 302. 

 Cydophorus {Myxostoma) troscheli, Chenu, Man. Conchyl. i, part 2, 



" 1860, p. 487, fig. 3595. 

 Pterocyclus cuminffLynv. troscheli, Nevill, Hand List, i, 1878, p. 261. 

 Pterocyclus troscheli, Kobelt & MiJllendorff, Nachr. Deuts. Malak. 



Ges. xxix, 1897, p. 114: id.. Cat. Pneiim. 1899, p. 26, p. 102 ; 



Kobelt, Das Tierreich, Lief. 16, 1902, p. 170: id., Conch.-Cab., 



Cyclophoridae, ii, 1910, p. 749, pi. 109, tigs. 13, 14. 



Original description : — " Testa latissime unibilicata, orbiculato- 

 depressa ; anfractibus 4 lente accrescentibiis, ultimo aiitice 

 subdilatato; apertura circulari, peristomate iucrassato, reflexo, 

 superne antice obsolete sinuato, ala cuciillata, autice an^ulata, 

 deflexa, anfi-actui penultimo adhaerente ; umbilico latissiino. 

 Operculo convexo, corneo. 



" Diam. major 20, minor 18 mill." (Benson.) 



Hah. Ceylon : Trincomalee (Bland). 



Genus PEARSONIA, Kohclt. 



Spiraculum (part.), Pearson, .L A. S. B. ii, 1833, p. 590; Adams, 

 Gen. Rec. Moll, ii, 1855, p. 278 (as snbgenus of Pterocyclos) ; 

 Blanford, J. A. S. B. xxxii, 1863, p. 319 ; id., A. M. N. H. ser. 3, 

 xii, 1863, p. 55 (animnl) : xiii, 1864, p. 451 ; Pfeiffer, Mon. Pneum. 

 Suppl. 3, 1875, p. 47 ; Fischer, Man. Conchyl. 1885, p. 745 (as 

 snbgenus) : Kobelt & Mollendorff, Nachr. Dents. Malak. Ges. 

 x.xix, 1897, p. 114 ; id.. Cat. Pneum. 1899, p. 26. 



Pearsonia, Kobelt, Das Tierreich, Lief. 16, 1902, p. 171. 



Type, Spiraciduin hisjyulum, Pearson. 



Range India and Farther India. 



Shell depressed, sub-discoidal, covered with a tliickperiostracum, 

 sometimes Iiaii-y; aperture circular; last whoi'l furnished, a short 

 distance behind the aperture, with a short reverted sutural tube, 

 open at both ends. Operculum multispiral, the edges of the 

 whorls projecting. 



Subgenus PEARSONIA, s. str. 



Spiraculum, s. str., Kobelt & Mollendorff, Nachr. Deuts. Malak. Ges. 



xxix, 1897, p. 114 ; id., Cat. Pneum. 1899, p. 26. 

 Pearsonia (subgenus), Kobelt, Das Tierreich, Lief. 16, 1902, p. 171. 



Type, S. Jiispidum, Pearson, 



Ranr/e. India and Farther India. 



Shell as in the genus ; basal margin of peristome without 

 process, 



160. Pearsonia andersoni, Blanford. 



Spiraculum andersoni, Blanford, Proc. Zool. Soc. 1869, p. 447; 

 Pfeiffer, Mon. Pneum. Suppl. 3, 1875, p. 49; Theobald, Cat. 



