NERITOPSIS. 343 



numerous coarse spiral bands, forming very prominent nodes at the intersections. 

 Aperture nearly circular. 



Relations and Distribution. — From Neritopsis varicosa, M. and L., this species 

 may be distinguished by its more angular and transverse form, by the almost 

 aborted spire, and by the exaggerated character of the radial costas. It is nearly 

 related to Neritopsis Hebertana, d'Orb., and might perhaps be regarded as little 

 more than a variety. The spiral belts are more numerous and less salient than 

 seems to be the case with d'Orbigny's species. 



This bizarre form was first noticed in the " Base-bed " at Lincoln, whence I 

 have obtained some characteristic specimens since the one figured on the 

 accompanying plate was drawn. A single specimen from the Nerinwa-bed in the 

 Pea-grit at Crickley. 



277. Neritopsis, cf. hebertana, d'Orbigny, 1852. Plate XXVIII, figs. 3 a, 3 b, 3 c. 



1852. Neritopsis Hebertana, d'Orbigny. Terr. Jur., vol. ii, p. 221, pi. ccc, 



figs. 1 — 4. 



Description .- 



Height ..... 12*5 mm. 

 Width . . . . .15 mm. 



Shell transversely oblong, angular, thick ; spire very short, composed of two or 

 three angular and rugosely ornamented whorls set in a sutural hollow, and 

 developing into a relatively enormous body- whorl, which is transversely oblong 

 and very angular. Four extremely prominent spiral bands are decussated by 

 radial costse of nearly equal strength ; the points of intersection are marked by 

 nodes which must have been extremely spinous. Aperture subcircular and wide, 

 but not sufficiently preserved in the available specimens for correct diagnosis. 



Relations and Distribution. — There is something in this form not exactly like 

 Neritopsis, and yet on the whole I think it must be regarded as an extremely rugose 

 relative of Neritopsis Hebertana. There are two specimens from Stoford (North 

 Dorset), and I have seen two more, which are stated to have come from the 

 Inferior Oolite at Bathford. 



