98 BRITISH BELEMNITES. 
rather wider than the dorsal, and the axes measuring 72 and 100. At the apex of the 
alveolus the inner layers have a somewhat less oval figure than the exterior ; and very 
near the axis they become undulated by the latero-dorsal facettes, but never show the 
deep grooving of B. Aalensis, B. quinquesulcatus, &c. Miller says the inner layers give 
a nearly circular section, but this is not the case in either of my specimens. Substance 
light-coloured, finely fibrous. 
Greatest length of axis 7; imches in a specimen 123 inches long; the diameters at 
the apex of the alveolus being under 1 inch from back to front, and above :ths from side 
to side. 
Proportions. The diameter, from front to back, at the apex of the alveolus being 
100, that from side to side is 72; the ventral radius 36, the dorsal 64. 
Puracmocone. Incompletely known, but presenting in fragments remarkable charac- 
ters ; oblique, with straight sides inclined at angles of 16° and 20° nearly. Section com- 
pressed elliptical, with axes as 88 to 100 near the apex, and as 83 to 100 near the 
aperture, the excentricity increasing with age. The septa are oblique, with slightly 
waved edges, siphon oval, submarginal, in a slight degree removed from the conjugate axis 
towards the right side of the animal. 
Depth of the largest chamber = one seventh of the diameter. 
Locality. In the Inferior Oolite of Dundry Hill. dZi/ler’s Collection in the Bristol 
Museum. In Mr. W. Sanders’s Collection and Prof. Phillips’ Collection. 
Odservations. Miller’s figures are very unsatisfactory, and his reference of fig. 17 in 
his essay to this species is a mistake. Many additional specimens are needed, especially 
young examples, but I think the main characters are clear for adults. The surface of 
some specimens is much worn and eroded ; Serpulee adhere to others. Belemnites longus 
of Voltz (Pl. IIL, fig. 1) is similar, but its apicial line is uniformly less excentric, and 
shorter in proportion ; it is from the Oolite of Buxweiler. Belemnites gladius of Blain- 
ville, from the Oolite of Bayeux, and from Rabenstein, is analogous if not identical. 
BeLemnites AALENSIS, Volfz. Pl. XXII, fig. 54; Pl. XXIII, fig. 55. 
Reference. Belemnites giganteus, Schlotheim, ‘ Petref.,’ p. 45 (probably), 1820. 
B. gigas, Blainville, ‘ Bélemn.,’ p. 91, pl. v, fig. 20 (probably), 1827. 
B. Aalensis,Voltz, ‘Obs. sur les Bélemn.,’ p. 60, pl. iv, pl. vu, fig. 1, 1830. 
B. Aalensis, Phillips, ‘ Geol. of Yorkshire,’ p. 166, 1835. 
Guarp. Sheath large, very much compressed, smooth. Anterior region unknown. Alveo- 
lar region cylindroid, often a little contracted in the middle. Apicial region (frequently) 
much contracted at a small distance from the alveolus, and thence extending into a long, 
