610 PLIOCENE MOLLUSCA. 



DistrihuHon. — Recent : Atlantic coasts of Spain, Madeira, Mediterranean 

 (widely diffused), Asiatic, ^gean. 



Fossil: St. Ertli. Pleistocene: Selsey. 



Miocene : Touraine, Anjon, Vienna l)asin. 



Pliocene : Astiano, Altavilla, Messina. 



Pleistocene : Livorno, Rhodes. Sub-Etnaen l)eds : Nizzeti. 



Remarls. — This southern species has been found rather commonly at St. Erth 

 by S. V. Wood, Messrs. Kendall and U. G. Bell and by Mr. A. Bell, having been 

 also reported by the latter from Selsey in a deposit the fauna of which is 

 distinctly of a southern character. It may be easily recognised by its form and 

 its strong sculpture. It is nnknown from the Anglo-Belgian Crag, though it had 

 a wide range in time from the Miocene of France and Vienna to the sub-Etnaen 

 beds of Sicily. 



The specimen from St. Erth now figured is from the Wood Collection at the 

 British Museum of Natural History. 



Alvania Wyville-Thomsoni (Jeffreys). Plate LI, fig. 18. 



1877—84 Bissoa ivyville-thoiusoni, Jeffreys iu Friele, Nyt Mug. Natur., p. 3, 1877; B. Wyville- 

 Thomsoni, in Lamphi<rh, Quart. Jouru. Geol. Soc, vol. xl, p. 321, p]. xv, fig. 3; Proc. Zool. Soc. 

 London, p. 122, no. 29, 1884. 



1893—1917. Bissoa Wyville-Thomsoni, A. Bell, Proc. Roy. Irish Acad. [3], vol. ii, p. 635, 1893; 

 Naturalist (Yorkshire), no. 723, p. 96, 1917. 



1901. Bissoa tvyville-thoiiq^soni, Friele og Grrieg, Norske Nordhav. Exp)ed., MoUusca-, pt. iii, p. 7'S. 



Specific CJiaracters. — Shell ovate, small, turreted ; whorls 5, convex, the 

 last much the largest, ventricose, the upper ones without sculpture, the lower 

 ornamented by numerous longitudinal cost;©, distinct but not prominent, which 

 hardly reach the base, and by fine, well-marked spiral ridges ; spire short, ending 

 in a small flattened apex ; suture deep ; mouth subcircular with a small umbilicus ; 

 outer lip thin, regularly rounded, slightly expanded. 

 Dimensions.— h. 3 nnn. B. 1'5 mm. 



Distribution. — Recent: "Lightning" and "Porcupine" Exped. (560 f.), 

 Noringen Exped., cold area (488^510 f.). 

 Fossil : Bridlington. 

 llemaiis. — llie Bridlington fossil here figured is one of a number found l)y 

 Mr. Bell among some loose stuff received from Mr. Headley. 



It agrees with Jeffreys' drawing of the original specimen which is in 

 Mr. Headley's Collection, bearing the identification of the author. I believe 

 these are the only fossil representatives of the species that have been recorded, 

 l)ut Ijeing a minute form it may have escaped notice elsewhere. Mr. Bell informs 

 me that it is one of the most common of the Bridlington Bissoas in Mr. Headley's 

 Collection. 



