2 Dr. J. C. Molvill on Marhw Mvlhisca 



iinishcd — to jnoperly examine these gatherings, a f;ict which 

 is not snrpiisinc; when the microscopic size of tlie bulk of the 

 material is considered. 



As is almost invariably the case in deep-sea ])roducts, the 

 predominating molluscan families are Pleurotomidso, first in 

 point of numbers, followed by Pyramidellidro, Trochidte, 

 Rissoidas, and Cerithidre. 



In the following descriptive paper I liave eliminated all 

 members of the secojul lamily named — Pyramidollidje, — as I 

 liave prepared, separately, a revision of the Gulf species, 

 which I hope may be published this autumn; but examj)le3 

 of the remaining and other families will be found among the 

 twenty-nine species now to be enumerated. 



The time does not seem to have arrived for a new edition 

 of the ' Catalogue of Gastropoda and Scaphopoda ' published 

 in 1901, though a considerable number of species could now 

 be added, and several emendations would likewise have to be 

 made at the same time. 



Including the Pelecypoda, the catalogue of which was 

 published only three years ago, tiie number of MoUusca 

 enumerated from these seas amounts to over 17(jO species, and 

 of these it has been found necessary to describe more than a 

 third as new to science. 



Acknowledgments are due to Mr. G. B. Sowerby, Mr. E. 

 R. Sykes, Mr. J. R. le Brockton Tomlin, and Mr. Edgar 

 Smith, I.S.O., while our sense of indebtedness to Mr. F. W. 

 Townsend has been, if possible, still further accentuated and 

 eniianced by the fresh services he has rendered to the science 

 of malacology during the past two years. 



Ct/closirema iredecimlinealum^ sp. n. (PI. 1. fig. 1.) 



C. testa depresso-discoidali, minufca, alba, delicata, late iimbilicata ; 

 anfractibus 4, quorum 1| apicales mamillati, laeves, nitidi, 

 CcEteris ad suluras leniter quasi-canaliculatis, peuultiino spiraliter 

 ;i-, ullimo 1.3-lineato— supra sex, infra septem lineis prsedito, — 

 liris indistinctis, hie illic fortioribu3 ; apertura obliqua, peristo- 

 inate rot undo, continue. 



Alt. J, diam. 2 ram. 



[Jah. Gulf of Oman, lat. 26^ 6' N., long. L(f 58' E., 15 

 fathoms. 



A rare and delicate species, white, discoidally depressed, 

 with large umbilicus, iour-whorled, two being apical, niamil- 

 late, the remainder ornamented with fine, somewhat indistinct 

 and unequal spiral lines, thirteen in all upon the body-whorl, 

 .«ix being on tlie upper side, and seven basal, round the 

 umbilicus. The periphery is not conspicuously angled. 



