﻿12 BRITISH BELEMNITES. 



Several foreign writers of eminence have incidentally noticed the more frequently 

 occurring British Belemnites, and in this manner, better sometimes than by the 

 descriptions or figures, we are able to establish, in a few instances, a satisfactory 

 synonymy with Schlotheim, Blainville, Voltz, D'Orbigny, Minister, Quenstedt, Oppel, 

 and Von Meyer. To these authors reference will be frequently made as we proceed. 



Lists of Belemnites, and scattered notices of individual species, have been often given 

 by British authors while describing particular strata or remarkable localities ; but there 

 is, perhaps, no group of fossils which demands so much caution in quoting references of 

 this nature to species not always really determined by examination of a large number of 

 specimens in different periods of growth. 



STRUCTURE OP BELEMNITIDiE. 



According to the knowledge now acquired, the solid parts of the Belemnitic 

 animal consisted of an internal shell of somewhat complicated structure, which for clear 

 explanation requires representations of at least three aspects of the surface and three or 

 more sections of the interior. By employing always fixed letters of reference for these 

 aspects and sections, the descriptions become more compact, symmetrical, and charac- 

 teristic. To begin with the principal sections, which are represented in the first diagram, 

 one being longitudinal, the others transverse — 



The portion of the Belemnite most commonly preserved in a fossil state is the 

 posterior or caudal part, marked G in the first diagram. It is to this sparry, usually 

 pointed, and more or less cylindrical, conical, or tapering mass, that the ancient dis- 

 cussions as to the horny, shelly, or mineral nature of the Belemnite belong. This was, 

 in fact, for Woodward and Lister the Belemnite. It has been called the guard, sheath, 

 rostrum, or osselet. 



In the transverse section taken at the apex of the phragmocone the concentric curves 

 represent successive stages of growth, the inner rings being deposited first, as in 

 exogenous trees. Indications of a thin capsule, or formative membrane, appear in some 

 Belemnites of the Oxford Clay and Lias, investing the guard. 1 In the Oxford Clay it is 

 represented by a granular incrustation ; in some Lias Belemnites it appears in delicate small 

 plaits, like ridges and furrows. The whole mass of the guard is fibrous, and usually 

 transparent carbonate of lime ; not exactly calcareous spar, unless we suppose a minutely 

 fibrous kind of crystallization, like that sometimes seen in stalactite. It is still more like 

 arragonite, and some kinds of recent shells, not such as Pinna or Hinnites, with large 

 prismatic cells, but, as Dr. Carpenter remarks, like Septaria. A distinctly cellular 



1 Mantel], ' Phil. Trans.' Owen, ' Phil. Trans.' Huxley, « Mem. of Geol. Survey.' 



