342 DR. GWYN JEFFREYS ON THE MOLLTISCA 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. 0-1. 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). 



2. Cioniscus striatus 1 , 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 strise 

 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 lip 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. 



i 1. Aclis ascaris, Turton. 



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



A. ascaris, B. C. iv. p. 102 ; v. p. 210, pi. lxxii. 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. Magnus Bay, Shetland, has a variciform rib. 



Fossil. Pliocene : Coralline Crag, Pisa (Manzoni), Tuscany (De 

 Stefani). 



There are some doubtful and obsolete synonyms of v. Muhlfeld 

 and others. 



1 Fluted. 



