CRYPTAULAX. 183 



Shell elongate, turrited, apex sharp ; spiral angle regular ; sutural sulcus 

 wide. "Whorls eight to ten, short, subpolygonal ; apical whorls more turrited in 

 some specimens than the anterior ones. The ornaments consist of from three to 

 four spinous or tuberculated spiral belts, of which the two outer ones are always 

 the strongest. The costas are from ten to twelve in number, and only moderately 

 twisted, in some varieties scarcely at all; usually the costae are not very pro- 

 minent. 



Body-whorl about one-fourth of the total height of the shell, in some specimens 

 slightly constricted anteriorly ; base depressed and spirally striated. Aperture 

 suborbicular, columella short and strongly encrusted. In some specimens there 

 are indications of the groove at the posterior angle. 



Varieties. — Fig. 12 a represents a specimen, from the Parkinsoni-zcme of Aston, 

 with four closely set spirals, and costae nearly straight and numerous. Fig. 12 b is a 

 specimen from the same horizon and locality with three spirals. This might be 

 almost called " triarmatum." Fig. 12 c is a specimen from the highest part of the 

 Humphriesianus-zone at Oborne. This is longer than usual, possesses four 

 spirals ; and the costas are not quite so close ; they are also more twisted. Fig. 11 

 represents a form apparently intermediate between G. tortilis and C. scobina. 



Relations and Distribution. — If we accept all the varieties above enumerated as 

 belonging to one species then it is somewhat difficult to see why Crypt, scobina 

 should not be included. The longitudinal costas in the latter species are less 

 numerous, and the ornaments less close. 



As regards distribution, Crijptaulax tortilis in this country is principally 

 confined to the higher zones of the Inferior Oolite. Besides the localities already 

 mentioned it is met with in the ParMns oni-zone at Grove. Aston and Notgrove 

 are the points farthest north where any of its varieties have come under 

 my notice. 



113. Cbyptaulax papillosa, Deslongchamps, 1842. Plate XI, fig. 13. 



1842. Cerithiuii papillosum, Desl. Mem. Soc. Linn. Norm., vol. vii, p. 209, 



pi. xi, figs. 42 — 44. 



Bibliography, Sfc. — Described from a single specimen of the " Oolite ferru- 

 gineuse," Bayeux ; considerably smaller than the specimen described below. 

 Description : 



Length . . . . .14 mm. 



Width . . . . .5 mm. 



Spiral angle ..... 20°. 



