BELEMNITES OF THE LIAS. 51 



dorsal radius 60, the transverse diameter, 94 ; the axis of the guard is about 300, 

 but is more or less according to age and range of natural variation. In my smallest 

 specimen the axis of the guard is 345. 



Phragmocone. Excentric ; transverse section a little oblong, longitudinal section a 

 little incurved, angle 25°. 



Localities. Crick Tunnel, specimen figured {Sowerby). Belemnite-bed, Lyme {Day, 

 Etheridye). Cheltenham {StricJcland). I have not seen this species in the strata of the 

 Yorkshire coast. 



Observations. There is no certain knovi^ledge of the specimens which served Mr. 

 Miller for the type of this species, nor is the figure which he gives, or the description 

 which accompanies it, at all critical. In fact, they have been interpreted so variously, 

 and referred to so many different species, as to be of Uttle or no authority. No grooves 

 are mentioned on the guard, which is merely described as " slender, tapering to a conical 

 point." The figure of Mr. Sowerby is taken from a fine specimen now in the British 

 Museum, and gives a good general representation of the fossil. The description, how- 

 ever, is not only incomplete, but inexact on an important point. " Slender, cylindrical 

 in the middle, gradually expanding to a broad base one way, and tapering to a point the 

 other ; round, d,w^ free from furrows ; the chambered cavity two thirds of the length of the 

 shell." The localities quoted are Charmouth, Bath, Crick Tunnel, all in the Lias. Instead 

 of being " free from furrows," the specimen has the usual two dorso-lateral grooves near 

 the apex clearly defined ; on the ventral aspect at the apex is a little elevated plait, but no 

 furrow. By these characters it belongs to the natural group of the ^' paxillosi ;' the 

 section of the guard is not quite round, even in old specimens, but always a little com- 

 pressed, often sensibly so when young, with an excentric axis ; the apex is more acute 

 than is usual with B. paxillosus, and the phragmocone is very much more extended than 

 in that species. 



The figure given in the monograph of the Geological Survey, already referred to, 

 agrees with the specimen in the British Museum and with several in my own collection 

 sent me from the " Belemnite Bed " of Lyme Regis by Miss Anning. For the drawings 

 on Plate VII, which represent the original specimen in the hands of Sowerby, I am 

 indebted to Mr. H. Woodward. Adopting the specimens preserved in the British Museum 

 and in Jermyn Street for types of the adult, I have attempted, chiefly by help of the spe- 

 cimens in my own drawers, to trace the younger forms, and determine the limits of varia- 

 tion to which the species is subject ; but I am not sufficiently provided with specimens, 

 especially for sections. 



In a specimen from Upper Lias, in my collection, which has the distinct lateral grooves 

 and the external characters of B. elongatus, there is a small, narrow, deep, stria on the 

 ventral aspect, close to the apex, and another on the opposite dorsal aspect. In another 

 example, also from the Upper Lias, and in my collection, both the dorsal and ventral sur- 



