254 THE VOYAGE OF H.M.S. CHALLENGEU. 



LinfKypsis, Sassi. 



Limopsis marionensis, u. sp. (PL XVIII. figs. 2—26). 



Testa valde insequilateralis, crassiuscula, oblique ovata, postice paulo augustata, 

 latere autico late arcuato, postico subacute rotundato. Valvas probabilitor albidse, 

 epidermideque hirsuta amictae, striis teuuibus uumerosis radiantibus aliisque couceutricis 

 decussatse. Area ligameuti profuuda, excavata. Dentes cardinis numerosi, cii'citer 20—2-1. 



This is a larger and more solid species than LimopsU straminea, and ditfers from 

 it also both in form and sculpture. It is not dilated posteriorly like that form, but ou 

 the contrary is even faintly pointed oi- at all events more sharply rouniled. The 

 sculpture is much stronger, and the hinge-teeth are more numerous. 



Length 28 mm., height 22, diameter 12. 



Habitat. — Station 145, Marion Island, in 140 fathoms, and Prince Edward Island, 

 in 100 to 150 fathoms. 



Ail the specimens of this species which were oljtained are old dead valves, and in 

 poor condition, but retain sufficient of their character's for description. 



Limopsis pelagica, u. sp. (PI. XVIII. figs. 3— iJa). 



Testa forma habitixqiie Limoj)sis marionensis sed sculptura dissimilis. Valv;B autice 

 et in medio striis punetatis teuuibus radiantilnis, postice liris tenuissimis elevatis incre- 

 menti lineis decussatis ornatfe. Ej^idermis pallide olivacea, tenuiter fibrosa. 



This species closely resembles Limopsis marionensis in form, the character of the 

 hinge, the ligamental area, and the interior of the valves, and is mainly distinguished by 

 a difierence of sculpture. This consists of numerous shallowly pitted radiating lines 

 which develop behind into slender lii-se, decussated by the concentric lines of growth 

 which are more elevated here and in front than vxpon the central jiortion of the valves. 

 The epidermis consists of very fine short pale olive fibres, which are very closely set 

 around the outer margin, forming a dense, soft fringe. 



Length 22 mm., height 20, diameter 9^. 



Habitat. — Station 106, Mid Atlantic, depth 1850 fathoms ; also Station 232, off 

 Inosima, Japan, at a depth of 345 fathoms. 



A single shell from the latter locality, dredged without the animal, I can in no way 

 distinguish from those obtained at a depth of 1850 fathoms in Mid Atlantic. This is 

 another instance, of which several have abeady been recorded, of shells found in Japanese 

 waters being identical with those inhabiting the Mediterranean and Atlantic Oceans. 



This species is very like Limopsis aarita, and may he only a large thin form of it. 



