DESCRIPTIONS OF SIXTY-EIGHT NEW SHELLS. 97 



know any Eiilima exactly comparable nor, we may add, so minute. We are 

 indebted to Mr. Sykesfor having extricated two examples from a mass of 

 shell-sand. 



R1SS0INA ISOSCELES-, sp. n. (PI. B. fig. 12.) 



R. testa eleganter attenuato-fusiformi, cinereo-alba, solidula ; anfractibus 9, 

 quorum 3 apicales hyalini, bulboso-globulares, cseteris longitudinaliter arete cos- 

 tulatis, apud supernos magis f ortibus, paucioribus, undique sub lente spiraliter 

 tenuissime striatis, infra peripheriam ultimi anfractus angulatam evanidis ; 

 apertura ovata, labro effuso, basim versus paullum producto, incrassato 

 columella obliqua. 

 Long. 5*25, lat. 2 mm. 

 Hab. Gulf of Oman, lat. 24° 58' N., long. 56° 54' E., 156 fathoms. 

 An attenuate graceful species of the typical section of the genus, angled 

 below the periphery, nine-whorled, the three globularly bulbous apical whorls 

 being distinctive, the longitudinal ribs on the fourth and fifth whorls being 

 fewer and more pronounced than on the lower — indeed they become obsolete 

 below the periphery of the body~whorl. With a lens the delicate spiral stria- 

 tion is discernible. Mouth triangularly ovate, outer lip produced at the base. 



RISSOINA (ZEBINA) REGISTOMOIDES, sp. n. (PL B. fig. 13) 



R. testa perminima, globulari, solidula, Isevissima, nitida ; anfractibus 5 

 quorum apicalis obtusus, vitreus, cseteris apud suturas subimpressis, ventri- 

 cosulis, ultimo paullum effuso, obliquato ; apertura ovato rotunda, labro 

 incrassato, albo, nitente. 

 Long. 2'25, lat. 1*50, mm. 

 Hab. Gulf of Oman, lat. 21° 58' N., long. 56° 54' E., 156 fathoms. 

 "Very minute, but extremely interesting. We are indebted to Mr. E. R. 

 Sykes for its discovery, while sorting shell-sand received from the above most 

 rich dredging. It is much smaller and more globose than any Zebina yet 

 described ; the peristome is wonderfully incrassate for so small a shell and 

 quite simple, never dentate, thus being unlike any of the numerous varieties 

 of R. tridentata, Mich., = Eidima curta, Sowb. The facies is eulimoid, but it 

 possesses the apex of Rissoina, and we are satisfied as to its location here. The 

 trivial name is suggested by its form, when magnified, though more globular, 

 somewhat resembling terrestrial Reg i stoma fuscum, Gray. 



EUL1MELLA CARMAN1CA, sp. n. (PI. B. fig. 14.) 



E. testa minuta, fusiformi, albo-lactea, lasvissima, polita, tenui ; anfractibus 

 8-10, quorum apicales heterostrophi, hyalini, lactei, cseteris fere rectis, apud 

 suturas leniter canaliculars, supernis paullum gradatis, ultimo recto, pro- 

 longate ; apertura quadratorotunda, labro recto ; collumella obliqua, simplici. 



Long. 4, lat. 1*20 mm. 



* }ao<jKi\r.s t from the basal shouldered angles. 

 13 



