374 On new Deep-sea MoUusca. 



dextra dente unico lateral! acuto postice instructus ; fossa liga- 

 menti parva, postice iDclinata. 

 Longit. 15 millim., alt. 11, diam. 9g. 



Hal. Off Andaman Islands, lat. N. 11° 25' 5", long. E. 

 92° 47' 6", in 405 fathoms. 



Closely allied to C. cusindata^ Olivi, but slightly different 

 in form and having a few radiating lines posteriorly. 



Myonera hicarinata. 



Testa a^quivalvis, ina^quilateralis, postice hians et breviter rostrata, 

 antice rotundata, alba, tenuis ; valvse tenues, inflata3, carinis 

 duobus acutis radiantibus post medium instructse, aute carinara 

 anteriorem concentrice subdistanter costulata), pone carinam 

 Iseves, lineis incrcmenti tenuissimis striata? ; umbones promi- 

 nentes, incurvati ; margo dorsi utrinque declivis, ventris antice 

 arcuatus, post et inter carinas excavatus ; cardo edentulus ; liga- 

 mentum internum in fossa angusta in utraque valva situm, 

 ossiculo tenui firmatum. 



Longit. 14 millim., alt. 11, diam. 9. 



Hah. West of Malabar coast, lat. N. 13° 47' 49", long. E. 

 73° 07' 0", in 636 fathoms. 



A very beautiful species, readily distinguishable by its 

 remarkable sculpture. The concentric costge on the anterior 

 half of the valves are finer and closer together towards the 

 umbo than towards the ventral margin ; they do not extend 

 quite to the submedian keel, and become finely attenuated 

 anteriorly. 



Lyonsia jucimda. 



Testa tenuis, fragilis, oblonga, antice rotundata, postice subtruucata, 

 a?quivalvis, incequilateralis, alba, radiatim carinata, carinis duobus 

 pot,t medium aliis majoribns, omnibus spinulosis vel tuberculatis, 

 undique minute granulata ; margo dorsi anticus rectiusculus, 

 valde declivis, posticus longior, minus obliquus, leviter concavus, 

 ventralis inter carinis siuuatus ; cardo edentulus ; ligamentum 

 internum ossiculo parvo munitum ; pagiua interna subnacrea, 

 radiatim sulcata, sulcis punctatis. 



Longit. 12^ millim., alt. 8, diam. 6. 



Hah. N. Sentinel, bearing N. 15° W. 18 miles, 250 fathoms. 



Cryptodon investigatorisy Smith. 



Oyptodon investigatoris, Smith, Ann. & Mag. Nat. Hist. 1895, vol. xvi. 

 p. 13, pi. ii. figs. 6, 6 a. 



Hah. Off west coast of Ceylon, lat. N. 8° 35' 45", long. E. 

 81° 17' 45", in 609 fathoms. 



