CULTELLUS. 



Species 1l'. (Mus. Brii.) 



CuLTELLUS GiiAXDis. Cal. tcftd inugnd, compressd, 

 utriiifjiu' hianti, albidd, j^rpureo radiatd, epider- 

 mide crassi, siibrirkli, nilenti indutd : iiitus casta 

 solidd, obliqud, infra umhoncm tilnhjui- valvd 

 munitd ; latere antico brevi, rotando ; medio paulu 

 excavato, marline ventrali concavo ; latere portico 

 expayisp, producto, subin/lato ; inarQine tcrminali 

 tmncalo : marr/ine dorsali compi'Cssn, el, rata. j)rope 

 umlxmes excavate. 



The large Cultellus. Shell large, compressed, 

 gaping at both ends, whitisli, rayed with piirple, 

 covered with a thick, greenish, sliining epidermis ; 

 fortified inside with a solid obliijue rib under the 

 umbo in each valve ; anterior side short, rounded ; 

 middle a little excavated, ventral margin concave ; 

 posterior side expanded, produced, rather iuflated; 

 terminal margin truncated, dorsal margin com- 

 pressed, elevated, excavated near the umboes. 



Gmelin. Linn. Syst. Nat. 



Hah. Arctic rcsions. 



?pecies lo. (^lus. Brit.) 



CcLTELLfs i;.\r>i.\Tcs. Cul. icsti'i elonrjald, coiiipresnd, 

 lenui, purptireo late radiatd ct concciitrice fasciatd, 

 ntrinque hianti, intics costd alba, validd, oMiqud 

 infra umhonem idrdqtie valvd mxtnitd, ; latere antico 

 hrcvitisculo, prope lunhones excavato ; latere postico 

 eloi/ijaio ; marginc dorsali. ntrinque rectiilsculo, 

 margine ventrali conve.vo, arctiato, utriiiqvv versiis 

 terminus acclivi. 



The r.\vei> Cl'ltellus. Shell elongated, compressed, 

 thin, broadly rayed and concentrically banded 

 with purple ; gaping at each end, fortified inside 

 with a strong, white, oblique rib under the umbo 

 in each valve ; anterior side rather short, ex- 

 cavated near the umboes ; posterior side elon- 

 gated ; dorsal margin rather straight on both sides^ 

 ventral margin convex, arched, sloping upward t(j- 

 wards the end on each side. 



LlNX^rs. Systema Xatura>. 



//((/;. Sum^itra. 



Species 14. (Mus. Brit.) 



Cultellus hosti;.\tus. Cm/, testa magna, comprc6i:d, 

 lata, elongatd, obscure pmrnureo radiatd ; epider- 

 mide crasso suhviridi indutd, inths costd validd 

 munitd ; latere antico breviiisculo, semiovalo ; latere 

 postieo attenuate, versiis terminum angustato, ad 

 ierminum latii truncate, margine dorsali cotnprcsso. 



The liEAKEi) Cultellus. Shell large, compressed, 

 broad, elongated, obscurely rayed with purjile, 

 covered with a thick greenish epidermis, fortified 

 within by a strong rib ; anterior side rather short, 

 semiovate ; posterior side attenuated, narrowed 

 towards the end, broadly truncated at the end ; 

 dorsal margin compressed. 



DuNKER. Proc. Zool. Soc, 18G1. 



Ilab. Arctic regions. 



It may be seen at once that this species, although- 

 bearing a general resemblance to Cultellus graiulis. 

 diilVrs from it in the posterior side tapering towards 

 the end, instead of being expanded and inflated. 



I.s7-i. 



