8 Mr. E. A. Sinitli on Mollasca from the 



Very like X. dorsaUs, but the valves are more equally 

 divided down the middle by the central groove, so that the 

 anterior and posterior portions are about equal. In X. dor- 

 sa/ls they are decidedly unequal, the posterior side being 

 conspicuously larger. This is clearly seen within the valves, 

 being indicated by the position of the strengthening rib. 



The sculpture on the anterior areas and the protoplaxes 

 are similar in both forms. I am inclined to think that the 

 latter will be found to be somewhat variable in form. 



Anatina andamanica, sp. n. 



Testa tennissima, subpiriformis, antice late rotundata, postirc obtuse 

 rostrata, ii)a?quilateralis, tequivalvis, mediocriter convexa, pellu- 

 cido-albida, lincis incremeuti striata ; umboues jiromineiites, 

 contigui, circitcr in ^ lougitudiuis collocati ; pagina interna nitida, 

 vix raargaritacea ; sinus pallii profunde rotundatus ; fulcra liga- 

 mcnti i)arva. 



Longit. 18 mm., alt. 14, diam. 10. 



Hab. Lat. 1 1° 32' N., long. 92° 46' E., off west of Anda- 

 mans, 194 fath. 



Shorter and rounder than many of the known forms. The 

 rostrate end exhibits slight traces of a periostracum. 



Euciroa eburnea (Wood-Mason & Alcock). 



Verticordia {Euciroa) eburnea, Wood-Mason & Alcock, Ann. & Mag. 



Nat. Hist. 1891, vol. viii. p. 447, fig. 14. 

 Verticordia optinia, Sowerby, Proc. Malac. Soc. vol. i. p. 30, pi. v. 



fig. 3 ; op. cit. p. 82, as V. eburnea, W.-M. & Al. 



Hub. Andaman Sea, 188-220 fath., and Stations 229 and 

 232, off Travancore coast, in 360-430 fath. 



Very similar to E. eJegantissima, Dall, from the Antilles, 

 and V. pacifica, Dall, fiom the Hawaiian Islands. Are they 

 sufficiently distinct to be regarded as different species, or are 

 they not merely variations of one widely distributed form ? 



It is curious to note that the localities of the three species 

 lie between 11° and 24" north of the equator, at depths 

 ranging from 188 to 756 fathoms, with a bottom-temperature 

 of 38°, 40°, and 55°. 



The size and number of the granules referred to by 

 Dr. Dall^ as distinguishing this species from E. eburnea are 

 variable, for in one specimen from the Andamans they are 

 quite as fine and as numerous as in one example of E. padjlca 

 in the ]Musenm collection. 



* Pioc. "U.S. Nat. Mus. 181)J., vul. xvii. p. (iSf). 



