CERITHIOPSIS TUBERCULARIS. 421 



1906. Cerithiopsis tuber cularis, Cossmami, Ess. Palcoconch. compar,, vol. vii, ]). 145. 



1908. Cerithiopsis tubercularis, Kobelt, Icon, schalentrag. europ. Meeresconch., vol. iv, p. 116, pi. cxx, 



figs. 1, 2, 3, 6, 7. 

 1912. Cerithium tuberculare, Tesch, Med. v. d. Itijks. v. Delfstoffen, no. iv, p. 76, no. 181. 



Specific C liaracter s. — Shell minute, solid, sub-cylindrical; whorls 13 — 14, 

 compressed, the last one-third the total length; spire slender, turreted, elongate, 

 becoming suddenly smaller near the apex ; embryonic whorls smooth, the others 

 ornamented by 3 rows of closely-set tubercles ; suture channelled, not deep ; base 

 angulate, slightly excavated, having two non-tuberculate ridges, one just below 

 the periphery; mouth, sub-quadrangular; canal short, sub-cylindrical, notched. 

 Dimensions. — L. 6 mm. B. 2 mm. 



Distribution. — Recent : coasts of Great Britain and Ireland from the Channel 

 Islands to the Shetlands and Orkneys. Mediterranean, Adriatic, Tripoli. North 

 Atlantic from Christiansund to Madeira. 



Fossil : Coralline Crag : Gedgrave, Sutton, Boy ton. Waltonian : 

 Walton-on-Naze. Newbournian : Waldringfield, Newbourn, Sutton. Butleyan : 

 Shottisham, Hollesley. Icenian : Bramerton. 



Casterlien (zone a Isocardia cor) : Belgium, Dutch borings. 

 Pleistocene : Clyde basin. 

 Holocene : Portrush. 



Miocene: France — Touraine; Italy (Elveziano, Tortoniano). 

 Pliocene : Piedmont, Siena, Parma, Messina, Altavilla. Normandy, Rhone 

 Valley, Biot. 



Pleistocene : Livorno, Valle Biaia, Messina, Ficarazzi, Monte Pellegrino, Tapes- 

 banks of Christiania. 



Remarks. — This species was obtained by Wood somewhat abundantly from 

 the Coralline Crag, but it is less common in the Red and Icenian deposits. Prof. 

 Brgrgger includes it in his list of Lusitanian species from the 7'r/y^ j .9-banks of 

 Christiania, and it has been found fossil in the Pleistocene deposits of the Clyde 

 basin as well as in the Holocene of Portrush in the north-east of Ireland, and 

 recent at Christiansund. As it is prevalently a southern shell, its occurrence so 

 far north may be a survival from the post-glacial times when milder conditions 

 obtained in those latitudes. 



According to Italian authorities, C. tubercularis was in existence in the Medi- 

 terranean region in the Miocene epoch. It had a wide Continental range during 

 the Pliocene, and occurs also in the post-Pliocene beds of Calabria and Sicily. 

 Prof. Sacco suggests it may have been derived from the Oligocene Cerithium 

 Htncheliusii of Nyst, with which it has been sometimes identified. 



M. Van den Broeck records it from the zone a Isocardia cor of Zwyndrecht 

 near Antwerp, and Dr. Tesch from beds of similar age met with in the Dutch 

 borings. 



