some new and peculiar Mollusca. 493 



The triangular shape (owing to the truncature of the pos- 

 terior side) J as well as the peculiar hinge-plate, will serve to 

 distinguish this species from A. crouUnensis and the young of 

 A . jiexuosus. 



LucinidsB. 



Diplodonta TorelW^, Jefir. 



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

 moderately convex but compressed, rather solid, opaque, of a 

 dull hue : sculpture^ numerous close-set but irregular concen- 

 tric strise, which are sometimes confluent, besides occasional 

 marks of growth : colour chalky : epidermis thin, yellowish- 

 brown : margins rounded on the anterior side, gently curved 

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

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

 about one tifth of the circumference : heahs small, somewhat 

 recurved towards the anterior side : lunule small, triangular : 

 ligament rather long, brownish -yellow ; groove deep : hinge- 

 line slightly curved : hinge-plate long, broad, and thick, taper- 

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

 teeth, in each valve two laminar cardinals (one of which is 

 bifid or double, as in D. rotundata) , a ridge-like lateral on the 

 posterior side, and a smaller and inconspicuous lateral on the 

 other side : inside frosted : j)allial and muscular scars as in 

 D. rotundata. L. 1. B. 1*1. 



Station 12, 1450 fms, ; fragments only. Spitzbergen 

 (Torell). 



I have described this species chiefly from a Spitzbergen 

 specimen, which my friend Professor Torell kindly gave me 

 at Lund. It is not gibbous like D. rotundata, broader in pro- 

 portion to the length, and differently sculptured. 



Cyprinidse. 



Isocardia cor, Linn^. 



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

 living at Station 12, 1456 fms., and at Station 16, 1785 fms. 

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

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

 from 50 to 1785 fathoms, and in the Mediterranean from 40 

 to 1456 fathoms. It literally swarms in Christianiafiord. 

 Full-grown specimens are comparatively rare, because the 

 habit of burrowing in mud prevents their being easily procured 

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



* Named in honour of the discoverer, Professor Torell. 



