BELEMNITES OF THE LIAS. 87 
Proportions. ‘The diameter (v @) being taken at 100, the ventral radius is 40, the 
dorsal 60, the cross diameter 100, the axis 420. 
Puracmocone. Nearly straight, with a nearly circular section; the angle 
m = 25°. 
Locality. In the lower part of the Upper Lias at Saltwick (Phz/iips) ; at Robin Hood’s 
Bay (Cullen); in ironstone layers at Kettleness (Simpson) ; in the shale under the Jet- 
bed, plentifully ; and in ironstone layers at Staithes and Rosedale (P£z//ips) ; in the Marl- 
stone series below the ironstone. 
Observations. The agreement of this Belemnite with that long known as B. pacillosus 
is obvious and intimate, and the resemblance of particular selected specimens is almost 
complete, the principal observable difference being a greater proportionate length of 
axis and a longer tapering to a less obtuse apex in the Yorkshire specimens. 
For comparison, a specimen from Ilminster, in Mr. Moore’s Cabinet, is represented 
fig. 52, MW. 
Recurvation of the apex occurs in several of the specimens of B. pawillosus, especially 
in those from Ilminster; in several of the specimens of B. cylindricus from Rosedale, 
near Staithes, it is so pronounced as to approach the form of B. aduncatus. 
On the whole, I can hardly doubt that the Yorkshire specimens agree with ZB. 
pacillosus amalthei of Quenstedt (‘Cephal.,’ pl. xxv, fig. 5); the state of conservation 
seldom allows of the striation of the apex to be perfectly seen, as in our representation 
of B. pavillosus (P). XX, fig. 52, AZ/). 
B. elongatus, B. apicicurvatus, B. paxillosus, and B. cylindricus, taken together, com- 
pose a natural group of generally cylindrical or cylindroid forms, with dorso-lateral grooves 
at the apex, and plaits or strize on the ventral and dorsal aspects (exceptionally, a deeper 
stria on the ventral and also on the dorsal face). They are unknown in Lower Lias, but 
extend from the base of the Middle Lias to the lower part of the Upper Lias, and are 
found in Dorsetshire, Gloucestershire, Northamptonshire, Lincolnshire, and Yorkshire. 
BELEMNITES OxYcoNUS, Quwenstedt. (Diagram, No. 23, p. 88.) 
Reference. Belemnites (tripartitus) oayconus, Quenstedt, ‘Cephalop., p. 419, 
pl. xxvi, figs. 19, 20, 1849. 
Guarp. Compressed, conoidal or conical, ending in a produced, pointed, somewhat 
reclined apex ; lateral grooves extend over the alveolar region. 
Transverse section oval, the ventral region broadest. 
Locality. Cheltenham, in the Belemnite-bed of the Lower Lias (Buckman). 
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