CERITHINELLA. 187 



exhibiting short, thick costce. Beyond this point the ornaments vary considerably 

 within certain limits. The upper spiral belt becomes a complex zone made up of 

 several spiral lines more or less undulating, which decussate with a system of 

 numerous short nodular costas ; about three spiral lines without any decussation 

 occupy the lower and more constricted portion of the whorl, which is terminated 

 by a nodular spiral belt, representing the lower of the two belts in the earlier 

 whorls. The above description only applies to very fully developed specimens. 



Body-whorl short, concave, and similarly ornamented ; base depressed and 

 somewhat excavated, marked with strong spiral lines. Aperture small, sub- 

 oblong, and somewhat constricted anteriorly. Anterior angle strongly marked, 

 but with scarcely any canal. A slight incrustation of the inner lip. 



Varieties. — With the above I associate provisionally two varieties, one of which 

 (fig. 2) occurs in the " Dew-bed " of Bradford Abbas. The proportions are 

 nearly the same, except that the body-whorl is somewhat shorter relatively. The 

 shell itself is more turrited and the whorls rather more angular ; the ornaments 

 also are less rich, the number of spirals especially being fewer. Altogether it is a 

 less well-developed variety. I propose to distinguish this as var. drosera. The 

 specimen is unique. 



The other variety (fig. 3) is from the neighbourhood of Beaminster, and 

 occurs, no doubt, on one of the lower horizons. The whorls are not angular, and 

 are separated by a very wide and shallow sutural sulcus. There is no turriting in 

 the sense of the succeeding whorls projecting beyond the preceding ones. The 

 ornaments are less elaborate ; the short costse in the posterior part of each whorl 

 are simpler, and have a decided twist from left to right. The specimen, which is 

 unique, exhibits an almost imperceptible fold in the outer lip, as in Nerincea. 

 This I propose to distinguish as var. melitta. 



Relations and Distribution. — But little more can be said at present on the 

 score of affinities. These beautiful shells are very scarce and never perfect. 

 Excluding the two varieties already named, the Soiverbyi-bed of North Dorset 

 alone has yielded these fossils. 



117. Cekithikella Brodiei, sp. nov. Plate XII, figs. 4 a, 4 b. 



Description : 



Length about . . . .30 mm. 



Width . . . . .6 mm. 



Spiral angle about . . . .10°. 



Shell subcylindrical; whorls numerous, angular, varying from subconvex to 



