PSAMMOTELLA. 



Genus PSAMMOTELLA, Bcshmjes. 

 Testa ovato - irmt-wena, couvexiusciila, subaquilateralis, 

 tttrinque hians, mike rotundata, podice longior, trun- 

 cata vel suhrostrata, concentrice striata, aut lutea aid 

 violacea, epidermide teniti decidud corned. Cardo 

 dentibits parvis centralibus erectis in valvd sinistra, in 

 valvd dextrd nnicd, callositate oblont/d in ambabiis. 

 Ligamentum externum. Impressio muscularis paltii 

 sinu oblongo peramplo. 

 Shell ovately transverse, rather convex, nearly equilateral, 

 gaping at botli ends, anteriorly rountled, posteriorly 

 longer, truncated or slightly beaked, concentrically 

 striated, yellowish or violet, with a thin horny deci- 

 duous epidermis. Hinge with two small erect cen- 

 iral teeth in the left valve, and one in the right, and 

 an oblong callosity in both valves. Ligament ex- 

 ternal. Muscular impression of the mantle distin- 

 guished by a very large oblong sinus. 

 This genus, of which we have here represented seven 

 species, was recently founded by M. Deshayes during an 

 examination of the family to which they belong, lately 

 made by that distinguished conchologist in the collection 

 of Sir. Cuming. While engaged in arranging the Psam- 

 moVuB and their allies, M. Deshayes recognized a distinct 

 generic type to which these were severally referable, 

 none of which had hitherto been descril)ed. They are 

 distinguished by. a pecularity of form, and they agree 

 especially in substance and tone of colouring. With a 

 convexly oblong nearly equilateral form, the posterior side 

 being rather the longer, they are all densely concentrically 

 striated, and either yellowish or deep violet, chiefly of the 

 latter colour, with a thin deciduous epidermis. 



So far as the localities are known, two are from the 

 Philippine Islands, one from Malacca, one from Ceylon, 

 and one from the Red Sen. 



irregularly plicatelj striated, whitish, covered towards 

 the margin with a fidvous epidermis, sides sloping at 

 the upper part, anterior rather narrowly rounded, 

 posterior obliquely attenuately truncated, lower mar- 

 gin semicircular. 



Deshayes, MS., Mus. Cuming. 



Uab. San Nicolas, Island of Zebu, Philippines ; Cuming. 

 Of light swollen structure, nearly equilateral, and ovately 



attenuated at each end. 



Species 2. (Mus. Cuming.) 



Ps.\MMOTELLA Malaccensis. Tsam. testa ovato-irans- 

 versd, tenui, cequilaterali, convexiuseuld, lavigatd vel 

 subtilissinie striata, pellitcido-albd, latere antico sub- 

 anguste rotundato, postieo subeompresso, truncato-ro- 

 tundato. 



TUE Malacca Psammotella. Shell ovately transverse, 

 thin, equilateral, slightly convex, smooth or faintly 

 striated, transparent white, anterior side rather nar- 

 rowly rounded, posterior somewhat compressed, trun- 

 cately rounded. 



Deshayes, MS., Mus. Cuming. 



Hab. Malacca. 



A small species, of simple form and semitransparent 



substance, the posterior side being rather i 



Species 1. (Mus. Cuming.) 



Psammotella Philippinensis. I'sam. testa ovato-trans- 

 versd, convexiuseuld, subcequilalerali, concentrice irre- 

 gidariter pUcato-striatd, albidd, epidennide fulvd ver- 

 ms marginem indtttd, lateribiis superne declivibus, an- 

 tico subanguste rotundato, postieo oblique attenuato- 

 truncato, margine inferiore semicirculari. 



The Philippine Psammotella. Shell ovately trans- 

 verse, rather convex, nearly equilateral, concentrically 

 March, 



Species 3. (Mus. Cuming.) 



Psammotella Skinneri. Psam. testa oblongo-transversd, 

 minute impresso-striatd, temdssimd, subvitred, lineis 

 nigricantibus undatis, radiisque duobus, notald, epi- 

 dermide corned olivaced nitente indutd, lateribus sub- 

 attenuatis, postieo breviore, vix truncato. 



Skinneii's Psammotella. Shell oblong transverse, mi- 

 nutely impressly striated, very thin, somewhat glassy, 

 marked with black zigzag lines and two rays, covered 

 with a shining olive horny epidermis, sides rather 

 attenuated, posterior rather shorter, scarcely trun- 

 cated. 



Eab. Ceylon ; Major Skinner. 



Of very distinct character from the rest of the genus, 



the shell being exceedingly thin and transparent, marked 



with bl-ickish zigzag lines, covered with a shining horny 



epidermis. 



