NO. 1342. SYNOPSIS OF THE ASTARTIDM-DALL. ()4(, 



Fy pe localit}^, off Icy Cape in 15 fathoms sand, W. H.^all. U.S.N.M 



No. 109276. 



Our specimens are somewhat more trigonal and attenuated heliiud 

 than in Leche/s figures. The sculpture is of quite even and regular sul- 

 cations which usually are somewhat less pronounced on the ventral third 

 of the disk, ])ut never present the striking- contrast hetween the sulcate 

 and unsulcate portions which may be nsually noted in ^1. fdhidn. In 

 many cases, however, the sculpture is continued to the base without 

 obsolescence, almost as evenly as in Hancock's imrhanu, but the shape 

 of the valves is different and the present species is much less in Hated. 

 Leche's figures 9 and 10 appear to represent J. /^//>/<^/, of wliidi 

 occasional specimens arc sulcate clear to the base, but which can usual! v 

 be recognized by the squarish and slightly wavy appearance of the 

 concentric umbonal sculpture. 



ASTARTE (RICTOCYMA) ESQUIMALTI Baird. 



Plate LXIII, tigs. 11, 12. 



This species having been figured only imperfectly, better figures are 

 now supplied from an adult specimen (U.S.N.M., No. 106802), dredged 

 near the Shumagin islands in 58 fathoms. 



VENERICARDIA CRASSIDENS Broderip and Sowerby. 

 Plate LXIII, tig. 9. 

 Astarte cruMklenn Bkodehh' and Sowekhy, Zool. Joui\, W , iSL'i), p. .j(>5. 



Ic}' Cape, Belcher, in Bland's collection (Broderip and Sowerby.) 



This species is described as '"■ obsoletely radiallv sulcate," nuich 

 eroded at the umbones, with a large striated cardinal in either valve 

 and with the margins coarsely crenulate, the crenulations having 

 "almost the appearance of low embrasures." It is represented as 

 reaching a length of 40, a height of 11, and a diameter of about 21 

 mm., with a tinge of dull reddish purple in the center of the valves 

 inside and the umljones nearly terminal and anteriorly directed. 



Now, these characteristics are not those of an Astarte. All ()ur 

 Arctic Astartes are white within; none is radiately sulcate: none has 

 embrasure-like crenations. Moreover, the vicinity of Icy Cape has 

 been pretty well dredged at various times, and Astarte is a gregarious 

 genus. If a species with such striking characteristics appeared there 

 somebody would have been almost certain to r(>coverit. But no spec- 

 imen is known, nor what became of that one which ser\ cd as the type 

 from "Mr. Bland's" collection. 



There is a shell which has been more than once ol)tainedat ley Cape 

 which fulfills the reciuirements, and that is the species of Vmericardia 

 identified by Gray with ''Arctaras /-^^^//n" (Humphrey .A[s.) in 188!>. 

 The radial sulcation, except on the umbones (which our authors state 



