the mollusc a of torres straits. 197 



Ungulikid^. 



394. DiPLODONTA ETHiMA *, sp. n. (PI. 11. figs. 17, 17 a.) 

 D. testa oblique globulari, tenui, profunde convesa, umbonibus 



contiguis, incurvis, margiue dorsali antice rapide declivi, rotun- 

 dato, postice primum fere recto, deinde abrupte marginem circa 

 ventralem rotundato, superficie extus alba, parum nitente, con- 

 centrice rudi-lirata ; pagina intus alba, cardine duobus dentibus 

 parvis in valva utraque prsedita, linea palliali simplici, inconspicua. 

 Alt. 11, lat. 11, diam. 8 mm. 



A tbin, globular, somewhat oblique Diplodonta ; the umboues, 

 owing to the great convexity of form, rather conspicuous and 

 incurved anteriorly. Though this shell possesses no very marked 

 characteristics, we have been unable to match it with any of the 

 numerous described species. 



395. Diplodonta subceassa, Smith. (Eep. Zool. Coll. Yoy, 

 H.M.S. ' Alert,' 1881-82, p. 104, pi. 7. figs. L, LI.) 



"We have been confirmed in our naming by the author, with 

 whom we compared our examples with the type, which came 

 from "West Island, Prince of Wales Channel (Station 9). 



396. Diplodonta subglobosa, Smith. (' Challenger ' Eep., 

 Lamellibranchs, p. 197, pi. 14. figs. 10, 10 a.) 



Two valves, on which Mr. E. A. Smith has also kindly pro- 

 nounced an opinion, remarking that these are more adult than the 

 types, and have a slight difference in shape. 



PSAMMOBTID^. 



397. PSAMMOBIA RASILIS f, Sp. n. (PL 11, fig. 18.) 



p. testa oblonga, tenui, fere Isevi, umbonibus inconspicuis, 

 roseo-suffusis, superficie carnea, longitudinaliter septem-radiata, 

 concentrice rudi-striata, margine dorsali antice recta, prolongata, 

 ad juncturam marginis ventralis uniangulata, postice abbreviata, 

 longitudinaliter corrugata, ligamento externo ; intus pallide 

 punicea, subpellucente, cardine in altera valva dente bifido, ia 

 altera indiviso, prsedita, linea palliali sinuata. Alt. 16, lat. 27, 

 diam. 3*50 mm. (spec. maj.). 



An elegantly rayed oblong species, almost smooth, tinted with 

 rose at the inconspicuous umbones, flesh-coloured as to its 

 * e'0j/xQS, usual, commonplace. t Basilis, smoothish. 



