508 PLIOCENE MOLLUSCA. 



Bemarls. — A passing reference was made to this well-known Crag shellin Vol. I 

 of the present work, but it was not figured. As I am now describing the other 

 species of Crag Trivias it seems desiraljle to represent a typical specimen of 

 T. europsea in order to show on the same plate the difference between them, and to 

 give also some further reference to the literature of the subject. 



Dimensions. — L. 6 — 20 mm B. 5 — 14 mm. 



Bistrihniion. — Recent: British Seas — Shetland to Guernsey. West European — 

 English Channel to Gibraltar, Mediterranean, Adriatic, JEgean. Norway — 

 Christiania fiord to Trondhjem, Lofoten Islands, widely diffused and alnindant. 



Fossil : Lenham, St. Erth, (coralline Cragj?as.sm. Red Crag — 

 Waltonian, Newbournian, Butleyan. Icenian : Thorpe near Norwich. Pleistocene : 

 Billock1)y, Gorleston, Selsey, Isle of Man, Clieshire, Lancashire, Yorkshire, 

 Kelsey Hill, Saltburn, Garvel Park, Largo, Cumbroe, Shewalton. Wexford to 

 Portrush. 



Belgium — Casterlien, Scaldisien, Poederlien. Holland — Scaldisien. 



Pliocene : Biot, Altavilla, Orciano, Bologna, Livorno, Messina, Gourbesville. 



Pleistocene : Monte Pellegrino, Ficarazzi, Catania, Reggio, Gravina, Livorno, 

 Valle Biaia. Tapes-banks : Christiania fiord. 



B.emarliS. — This species, varying in size from var. vdnor to var. splifvviculata, 

 the last a Miocene form, is very abundant in the Red Crag, especially at Oakley, 

 where I have collected many specimens. In the Icenian Crag it has only been 

 reported from one locality, the well-known but now inaccessible pit at Thorpe near 

 Norwich, from which formerly so many interesting fossils were obtained. It would 

 not be difficult to obtain permission to re -open this famous section, l)ut at present 

 but little local interest is taken in the subject. The wonderful success which has 

 attended the exploration of the Little Oakley pit, the existence of which was 

 discovered almost by accident, should stimulate similar inquiry elsewhere. 



Trivia retusa (J. Sowerby). Plate XLV, fig. 8. 



1823. Cyjprpea relusa, J. Sowerby, Min. Concli., vol. iv, p. 107, pi. ccclxxviii, fig. 2. 

 1842 — 48. Trivia retusa, S. V. Wood, Ana. Mag. Nat. Hist. [1], vol. ix, p. 544, 1842 ; Cypr.va retusa, 

 Mon. Crag Moll., pt. i, p. 16, pi. ii, fig. 8. 



1871. Ci/priea retusa, Jeffreys in Prestwich, Quart. Jonrn. Greol. Soc, vol. xxvii, pp. 143, 488. 



1872. Gyprxa retusa, A. and R. Beil, Proc. Geol. Assoc, vol. ii, pp. 203, 209, 213. 

 1881. Cyprtea retusa, Nyst, Couch. Terr. tert. Belg., p. 60, pi. v, fig. 3. 



1890. Cyprxa retxisa, C. Reid, Plioc. Dep. Brit., p. 243. 



1892. Cyprsea retusa. Van den Broeck, Bull. Soc. Beige Gcol., vol. vi (Mcmoires), p. 147. 



Specific Characters. — Shell small, ovato-globose, ornamented by a comparatively 

 small number of transverse ridges, without dorsal furrow ; mouth sub-central. 

 Dimensions. — L. 10 mm. B, 8 mm. 



