Bay of Bengal and the Arahian Sea. 2G3 



shell, however, is different in size and shape and the rij^ht 

 valve is less distinctly keeled posteriorly. C. bifrons, 

 A. Adams, is another allied form. The white ribs, which 

 contrast strongly with the yellow nnclear shell, are about 

 seventeen to twenty in number. The right valve exhibits a 

 faint rounded angle from the umbo to the lower corner of 

 the posterior end, but less pronounced, than that in C. Philippii. 



Corhula andamanica, sp. n. 



Testa C. perslccn similis, sed postice minus distincte truncata, valva 

 dextra ad umbonem magis producta, costis tenuioribus, magis 

 numcrosis instructa. 



Longit. (j'o mm., alt. G, diam. 4. 



Hab. Off Port Blair, Andaman Islands, 100 fath. 



Very like C. persica, yet diftering in the points indicated. 

 The ribs, wliich are dirty yellowisli, are about twenty-five in 

 num])er. C. albuginosa, Hinds, is closely allied, but longer, 

 and with the right valve more finely sculptured. 



Solecurtus {Azov) coarctatus (Gmelin). 



Solecurtus {Azov) coarctatus (Gmeliu) ; Smith, Lamellibranchiata 

 * Challenger ' Exped. p. 79. 



Hab. Station 295, Gulf of Oman, 37-40 fath. 



Also known from the Nicobar and Philippine Islands. 

 The synonymy and some remarks upon this species are given 

 at the above reference. 



Lyonsiella papyracea, Smith, 



Lyonsiella papyracea, Smith, ' Challenger ' Lamellibranchiata, p. 73, 

 pi. XXV. tigs. 2-2 h ; Pelseneer, Anat. ' Challenger ' Deep-sea Moll. 

 p. 18, pi. ii. fig. 8. 



Hab. Station 276, W. of Ceylon, 1006 fath. (^Investi- 

 gator^) ; about 1100 miles south-west of Australia, in 

 1950 fath. {' Challenger '). 



The single specimen differs from the type in having more 

 numerous radiating threads, about fifty-six altogether. It is 

 rather larger and less fragile, and has a somewhat thicker 

 and coarser periostracum. The form is very similar, although 

 not absolutely identical ; but that is a character which is 

 liable to considerable variability. 



19* 



