Bdji (if BriKjal (iiid the Arahi ni Sta. 257 



at once removes this species from Cri/ptodon, which is eden- 

 tulous. I am incliued to refer it to the genus Lori/jcs, with 

 which it is practically identical in dentition, but the ligament 

 is not (juiteso deeply placed within tiie dorsal margin. 



Lucina dentifera, Jonas. 



Lucinn dentifera, Jonas ; Sinitli, Aim. & Mag. Nat. Hist. 1904, vol. .yIv. 

 p. 10. 



Hub. station 34,6, Persian Gulf, 47 fath. 



Lucina bengalensis, Smith. 



Lucinn benc/alensis, Smith, Ann. & Mag. Nat. Hist. 1894, vol. xiv. 

 p. 171, pi. V. tig3. 1, 2 ; 1904, vol. xiv. p. 10. 



Hab. Station 261, W. of Cape Coraorin, 386-44-5 fath,, 

 green mud and sand ; Station 323, N. of Andaman Islands, 

 463 fath. 



Cnjptodon investh/atoris, Smith. 



Cryptodon invest!(iatoris, Smith, Ann. «fe Mag. Nat. Hist. 18.95, vol. xvi, 

 p. 13, pi. ii. tigs. 6, Ga; 1896, vol. xviii. p. 374 ; 1904, vol. xiv. 

 p. 10. 



Hab. Station 336, W. of Ceylon, 603 fath. 



Cryptodon omanensis, sp. n. 



Testa quadrato-rotundata, compressa, inaequilateralis, alba, lineis 

 incremenli tenuibus oriiata, striisque radiantibus tenuissimis 

 Timbones versus sculpta ; lunula parva, excavata, circumscripta ; 

 unibones autemcdiani, acuti, approximati, ad apicem lagves ; liiiea 

 cardiuis leviter incrassata, Itevis, edcntula ; ligamcntum in sulco 

 angusto profundo intra margiiiem situin ; valvie subtenues, intus 

 radiatim tenuiter striata?, cicatrice angusta, baud profunda, ab 

 umbone margincm vontralem versus extendeute sculptoe ; cicatrix 

 antica angusta, lougit. 10 mm., intra lineara pallii sita, postica 

 brevior, latior. 



Longit. 26 mm., alt. 24, diam. 10. 



Hab. Station 341, Gulf of Oman, 230 fath. 



A flat compressed species like C. barbatus (Reeve), but 

 thinner, lighter, and different in form. The concentric 

 sculpture is very fine and at each side is slightly lamellated. 

 The anterior and po.-terior ends arc both somewhat roundly 

 angulated and the ventral margin shar[)ly arcuate. 



