MULTILOCULAR SHELLS. 259 



and hence, the line running internally, from that apex to the point of 

 the belemnite, is nearest to the same side. For this reason, we 

 may name this species b. excentralis. It is found in the oolite, the 

 upper shale, and the chalk. The specimen, Fig. 4, which is from the 

 oolite, is large, but imperfect. In its entire state it has probably 

 been a foot long. The belemnites in the shale at Speeton seldom 

 reach half that length ; and are commonly much mutilated, the 

 alveolus being lost. 



No. 2 is the b.fusiformis of Parkinson. It is from the Speeton 

 shale, and like all the specimens which we have seen, is imperfect, 

 the conical broad termination, containing the alveolus, having been 

 broken off at the narrow neck. The form of the entire shell may be 

 seen in Parkinson's Org. Rem. III. PI. VIII, Fig. 1 3. Our fossil some- 

 times displays two faint longitudinal furrows, or grooves, on opposite 

 sides; but it is remarkably round and smooth. The internal line 

 passing to the point is quite central ; and the transverse section not 

 only shews diverging rays, but concentric circles crossing them, as 

 in some madrepores. In the Speeton shale, this fossil is often highly 

 translucent, as is the case with b. excentralis, but in the Staiths beds, 

 where we also discovered it, it shews the same dark grey and nearly 

 opaque spar as the b. vulgaris. It occurs also, but rarely, in the lias 

 nodules. Some specimens in the upper shale are very small ; and 

 hence they have been taken for spines of echini. 



No. 6 is a very singular belemnite, from the alum shale at Salt- 

 wick, the only place where we have found it. The alveolus is 

 conical and nearly central, as in No. 1 ; and, as in that species, is 

 often replenished with pyrites and occasionally with galena : but the 

 body, or sheath, is very long, slender, and cylindrical. Some of our 

 specimens are about a foot in length, of which the alveolus occupies 

 scarcely more than two inches ; whereas in b. vulgaris, the alveolus 

 is sometimes more than half the length of the entire shell. Another 



