342 DR. GMfYN JEFFREYS ON THE MOLLtJSCA OF THE [May 20, 



more round than oval ; peristome continuous or complete : outer lip 

 flexuous, usually strengthened by a rib, contracted above : inner lip 

 attached to the pillar, which is oblique ; there is no umbilicus. 

 L. O-I. B. 0-025. 



'Porcupine' Exp. 1870: Atl. St. 17a, 26-30,33; Med. 55. 



Distribution. Bay of Biscay ('Travailleur' Exp.), Tunisian coast 

 {Nares and Dautzenberg), S. Vito (Monterosato), off the west coast 

 of Africa and the Azores ('Talisman ' Exp.) ; 108-1622 fms. 



Fossil. Pliocene : Messina {Seguenza). 



1^ 2. CiONiscus STRiATUS^ Jeffreys. (Plate XXVI. fig. 2.) 



Shell forming an elongated column, thin, semitransparent, and 

 glossy : sculpture, close-set, thread-like, and flexuous longitudinal 

 ribs, about twice as many as in the last species ; they do not extend to 

 the base of the shell ; one at least of these ribs is varicose or larger 

 and thicker than the rest , there are slight indications of spiral striae 

 under the microscope ; the two apical whorls are quite smooth or 

 polished : colour whitish : spire elegantly and gradually tapering to 

 a blunt and bulbous point : whorls 8, convex and rounded : suture 

 deep and well defined : mouth roundish-oval ; lips disunited : outer 

 lip contracted at the upper corner : inner Up adhering to the pillar 

 and resembling a thin glaze : umbilicus none, but the base is some- 

 what depressed. L. 0-15. B. 0-05. 



'Porcupine' Exp. 1870: Atl. St. 16. Four more or less perfect 

 specimens. 



Distribution. Tunisian coast (Nares), off the Sahara and west 

 coast of Africa ('Talisman' Exp.) ; 300-1261 fms. 



In the last ' Talisman ' Expedition occurred another species of 

 Cioniscus, which will be named and described by Dr. Fischer or the 

 Marquis de Folin. It is larger than either of the species now de- 

 scribed ; the ribs are straight, and do not extend below the periphery; 

 and the mouth is longer. 



•/ 1. AcLis ASCARis, Turton. 



Turbo ascaris, Turt. Conch. Diet. p. 217. 



A. ascaris, B. C. iv. p. 102 ; v. p. 210, pi. Ixxii. fig. 2. 



'Porcupine' Exp. 1869: St. 2, 18. 1870: Med. Adventure Bank. 



Distribution. W. & S. Norway to Crete; 15-120 fms. Occurs 

 with A. supranitida, but both species have been apparently con- 

 founded in local catalogues. The present species is much smaller 

 and narrower ; and it has no umbilicus. A. supranitida is larger, 

 and more conical or wider at the base ; and the umbilicus is very 

 conspicuous in every state of growth. A specimen of A. ascaris, 

 which was found by the late Mr. Robert Dawson in shell-sand from 

 St. Magnu.s Bay, Shetland, has a variciform rib. 



Fossil. PHocene : Coralline Crag, Pisa (Mamoni), Tuscany (De 

 Ste/ani). 



There are some doubtful and obsolete synonyms of v. Muhlfeld 

 and others. 



1 Fluted. 



