some neic and pcculuir Mollusca. 403 



Tho triaiiiiular shnpo (owiiiLj to tlio truncaturo o( the pos- 

 terior siile\ as well as tho peculiar hinge-plate, will serve to 

 distinguish this species from A. crouh'ncnsis and tiie young of 

 A. f/i\t'H(tsus. 



Lucinidffi. 



Diph^fonta Torelli*, Jeflr. 



Shell roundish-oval, inequilateral, with an oblique outline, 

 moderately convex but couquessed, rather solid, opaque, of u 

 dull hue : acufptuir, numerous close-set but irregular concen- 

 tric stria\ which are sometimes continent, besides occasional 

 marks of growth : colour chalky: tju'dcnnis thin, yellowish- 

 brow n : man/ins rounded on the atiterior side, gently curved 

 in front, rounded and expanded on the posterior side, and 

 slojnng gradually at the back from the beaks to the extent of 

 about one tit'th oi^ the circumference : />i'<iA>" small, somewhat 

 recurved towards the anterior side : litnah' small, triangular : 

 //}/< I //«■/</ rather long, brownish-yellow ; groove deep : /iin(/e- 

 litw slightly curved : /iii)</e-phiti' long, broad, and thick, taper- 

 ing towards each end, placed mostly on the posterior side : 

 tirt/i, in each valve two laminar cardinals (one of which is 

 bitid or double, as in />. rofumlota^, a ridge-like lateral on the 

 posterior side, and a smaller and inconspicuous lateral on the 

 other side : //»x/We frosted : palliul ond muscular scars as in 

 D. rotumhito. L. 1. B. II. 



Station 12, 14J0 fms. ; fragments onlv. Spltzberc:eu 

 (Torein. 



I have described this species chietly from a Spit/.bergeu 

 specimen, which my friend Trofcssor Torell kindlv gave me 

 at Lund. It is not gibbous like />. rotiindato, broacler in pro- 

 portion to the length, and ditVerci\tly sculptured. 



CyprinidsB. 



Isocardia (\>r, Liunc. 



The try or very young of this well-known species occurred 

 living at Station 12, 14,")(.; fms., and at Station U>, 17S5 fms. 

 In this stage of growth it has a wide distribution in the North 

 Atlantic, from the Loffodcn Isles to the Azores, at depths of 

 from .")(> to 178") tathoms, and in the Mediterraneaii tVom 40 

 to 14.")() tathoms. It literally swarms in Christianiatiord. 

 Full-grown specimens are comparatively rare, because the 

 habit of burrowinu: in mud prevents their being easily ^irocured 

 by means of the dredge or trawl. I have a series ot various 



♦ Nnmod in huuoiu- of tho discoveror, Professor TorvU. 



