138 



the top to the under part of the base, will readily distinguish 

 this from all other forms. 



This is the most abundant form even at Coker, where a band 

 of the cephalopoda bed is for the most composed of these sinistral 

 shells. It is met with at Bradford Abbas, Half Way House, 

 Dundry, always in the same horizon in both Dorset and Somerset, 

 but we have never met with any of these sinistral shells in 

 Gloucestershire. 



CIRRUS INTERMEDIUS, Buckman, pi., fig. 4 and 4a. 

 ,, NODOSTJS, Sow. M. C., t. 141, f. 2. 



Acutely conical, spire reversed, with two obscure transverse 

 carinae, upon which are numerous longitudinally extended tuber- 

 cles ; aperture orbicular.* 



In this shell the spire is more symmetrical than in the other 

 species. The lower whorl is scarcely out of proportion to the 

 others. Sowerby, in describing this form, says: " There are 

 two rows of tubercles on each whorl, formed by the intersection 

 of transverse and longitudinal ridges, the upper row is largest, 

 and the other is inconspicuous. The aperture seems from the 

 cast to have been somewhat plaited." 



Dr. Leach some years since presented me with this specimen, 

 picked up near Yeovil : it is a reverse shell, and seems to have 

 been gregarious : two were here crowded together : there were 

 signs of ammonites in the mass. It had apparently a very 

 acuminated spire, seven turns of which remain, and space above 

 for as many more, according to the general proportions.! 



The acutely spiral form of this shell, so different from the C. 

 nodosus, f, 3 and 3a, would seem to be sufficient to separate this 

 from the later named C. nodosus, M. 0., pi. 219, fig. 4. The flat 

 spire of our figs. 3 and 3b, when compared with the elevated 

 figs 4 and 4a, sufficiently points out the difference. If then figs. 

 4 and 4a be not distinct from figs. 3 and 3a, they are more nearly 



* Sow., M. C., Vol. 2, p. 94. 

 t Ibid, Vol. 2, p. 94. 





