BELEMNITES OF THE OOLITE. 105 
“1720. Belemnites (cylindraceus) forme compressioris, fissura altero latere donata, 
é fodinis Stunsfeldiensibus.” | 
The specimens thus referred to by numbers cannot now be recognised in the Oxford 
(“ Ashmolean”) Museum. 
Platt, in 1764, illustrates his sensible account of the ‘Origin and Formation of the 
Extraneous Fossil called the Belemnite’ by instructive figures of fusiform specimens from 
“Stonsfield” and Piddington, the latter being found in Oxford Clay. On his pl. iv, 
fig. 3 represents the Piddington fossil, with a groove not reaching to the alveolar region, 
' while fig. 2 shows the completely grooved surface of the Stonesfield fossil, as may be seen 
by the diagram below, which is copied from Platt. 
DIAGRAM 28. 
Parkinson’s ‘ Organic Remains of a Former World’ presents to us the fusiform Belem- 
nite of Stonesfield, in vol. ii, pl. 8, fig. 13; the lateral and retral expansion of the guard 
being greater than usual. 
Miller, in the ‘ Geol. Trans.,’ 2nd ser., vol. ii, pl. viii, fig. 22, gives a figure of the 
same unusual proportions, but with the peculiarity that the ventral groove does not 
extend over any part of the alveolar cavity, a circumstance never yet observed by me 
among upwards of twenty specimens from Stonesfield. 
Morris and Lycett, in the ‘ Monographs of the Palzontographical Society,’ give figures 
and descriptions of the Belemnites of Stonesfield, under the names of B. Bessinus (adopted 
from D’Orbigny) and B. fusiformis (vol. for 1850, pl. i, figs. 5 to 8). The figs. 5 and 7 
for B. Bessinus differ scarcely in anything from figs. 6 and 8 for B. fusiformis, except 
that these latter are slightly swollen in the middle part of the post-alveolar region. These 
authors regard ZB. fusiformis as the equivalent of B. Fleuriausus of D’Orbigny. But the 
author of the ‘ Paléontologie Francaise’ was of a different opinion, and placed B. fusi- 
formis of Miller among the many synonyms which he quotes with B. hastatus of Blain- 
ville. In Pl. XXVI all the different forms of Stonesfield Belemnites as yet discovered are 
represented ; they all possess a depressed post-alveolar region, and a ventral sulcus reach- 
ing far toward the apex, and extending considerably in the alveolar region. 
