448 Messrs. J. Wood-Mason and A. Alcock on 



valve, and an anterior tooth in the form of a broad and stout- 

 based projecting massive hook, which is received into a notch 

 of the lefit valve lying beneath the umbo between the liga- 

 mentary fossa and the lunule. Except for a mere film joining 

 the valves externally in the usual position the ligament is 

 internal. A stout, convex, posteriorly-bifid ossicle connects 

 the ligaments of the valves with one another. 



Most striking is the curious lunule, which suggests in-turned 

 ears. 



A fine living specimen from Station 115, 188 to 220 

 fathoms, measuring in length 37 millim., in height 3;j'2 

 millim., and in thickness 26"8 millim. 



21. VerticordiUj sp. 

 From the Bay of Bengal, in 1997 fathoms. 



Family Tellinidae. 

 22. Tellina^ sp. 



Two species were dredged, one from the Bay of Bengal at 

 561 fathoms, the other from 922 fathoms in the Andaman 

 Sea. 



Subgrade C(EL EN TEE A TA . 



Piiylum NEMATOPHORA. 



Class SCYPHOMEDUS^. 



Order PEROMEUUStE. 



Family Periphyllidae. 



Peeiphylla, Steenstrup. 



1. Periphylla, sp. 



A large species, with the internal organs ratlier ragged, 

 from Station 120, 240 to 276 fathoms. 



Order DISCOMEDUS^. 



Family Ephyridse (CoLLASPiDiE). 



Atolla, Haickel. 



2. Atolla Wyvilliiy Haickel. 



Atolla Wyvilli,l\xc\\.^\, ' Challen^'er ' Deep-sea Medusae, pp. 113-123, 

 pi. xxix. 



