258 THE VOYAGE OF H.M.S. CHALLENGER. 



afute when not eroded at the tips as is frequently the case, and located a trifle in 

 advance of the middle. The dorsal area is narrow, elongate-elliptical, rather deeply 

 concave, of a light brown colour, and provided with a diamond-shaped central dark 

 brown ligament. The hinge-teeth are strongish, in an almost straight series, and 

 number about eight or nine, of which two or three more are on the anterior side of the 

 beaks than behind. The interior of the valves is dull whitish, rather roughish, 

 exhibiting a kind of shallow pitting or subjxmotation. The outer margin is thickened, 

 distinctly dentate interiorly, and crenulated at the sides. 



Length 8^ mm., height 8^, diameter 4f. 



Habitat. — Station 169, off the north-east coast of New Zealand, at a depth of 

 700 fathoms. 



This little species is peculiar for its width, comparative solidity, and dentate margin, 

 and bears considerable resemblance to Limopsis minuta. 



Limopsis minuta (Philippi). 



Pediinculus minuta, Philippi, Enum. Moll. Sicil., vol. i. p. 63, pi. v. figs. Scr, 3ft, vol. ii. p. 45. 

 Limopsis minufa, Siirs, Moll. Eeg. Arct. Norv., p. 44, pi. iii. figs. 5, a-c. 

 Limopsis minuta, Jeffreys, Proc. Zool. Soc. Lond., 1879, p. 585, pi. xlvi. fig. 9. 



Habitat. — Station II., off east coast of Portugal, in 470 fathoms; Station 75, Fayal, 

 in 450 fathoms; Tenerife, in 70 fathoms; Station VIII., Canary Islands, in 620 fathoms; 

 and Station 24, off Culebra Island, West Indies, in 390 fathoms. 



For the synonymy and distribution of this species consult the above paper by Dr. 

 Gwjm Jeffreys. I agree with him in considering Limo^jsis abyssicola, A. Adams, the 

 same as this species, but do not think that Limopsis cumingii of that author is 

 conspecific with Limopsis aurita, Brocchi. 



Subfamily Arcing. 



Area, Linne. 



Area noce, Linne. 



Area nocB, Linn^, Syst. Nat., ed. 12, p. 1140. 



Area noce, Eeeve, Conch. Icon., vol. ii. pi. xi. fig. 72. 



Habitat. — Station 36, off Bermuda, in 32 fathoms. 



This well-known Mediterranean and West Indian species in the very young state 

 has at times the posterior side deeply notched. 



