MOLLUSCA FROM THE GREAT OOLITE. 
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AmMONITES ARBUSTIGERUS, D’Ord. Plate II, figs. 4, 4a. 
AMMONITES ARBUSTIGERUS, D’Orb. 1848. Pal. Frang., Terr. Jur., p. 414, t. 143. 
—_ — D’ Orb. 1850. Prod. Paléont., p. 296. 
A. Testa compressa, anfractibus rotundatis, latis, lateribus convexis transversim 22 
costatis ; costis obtusis bi-trifurcatis vel intermediis, dorso subsconvexo ; apertura oblonga, 
compressa. 
A discoidal, costated shell, with somewhat convex and gradually increasing volutions ; 
umbilicus large : the principal costz are obtusely rounded, and about twenty-two in number, 
bifurcating as they pass over the back, having occasionally an intermediate mb; back 
convex ; aperture oblong. 
Locality. n the Great Oolite of Minchinhampton, and described by M. D’Orbigny 
as occurring both in the Great and Inferior Oolite of Normandy. 
Ammonites MACROCEPHALUS, Sch/oth., var. Plate I, figs. 3, 3a. 
AMMONITES MACROCEPHALUS, Schloth. 1813. Min. Tasch. vii, p. 70. 
— Schloth. 1820. Petref., p. 70, No. 16. 
= — Zieten. 1850. Pet. Wurtemberg, t. 5, f. 1, 4. 
— = D Orbigny. 1848. Pal. Franc. Terr. Jur., p. 430, t. 151. 
= _ D Orbigny. 1850. Prod. Paléont., p. 127. 
A. Testé discoided, sub-globosd, anfractibus involutis, rotundatis, costatis: costis 
20—30 obtusis, medio laterum bifurcatis ; apertura semi-ellipticd ; umbihco subcontracto. 
An inflated, or somewhat globose shell, with rather depressed volutions, and a narrow 
and deep umbilicus, from the margin of which arise about twenty to thirty obtuse ribs, 
which bifurcate in passing over the back. Back convex ; aperture semi-elliptical. 
We have ventured to assign our specimens to the Ammonites macrocephalus of 
Schlotheim, although their imperfect state of preservation renders this identification 
somewhat doubtful. The specimens of this species hitherto obtained by us from the 
Oolite, are always in the state of casts, and very much eroded, so that the principal ribs 
which surround the umbilical cavity, are nearly obliterated, as shown in the figure, 
tab. 2, fig. 3. 
Locality. Great Oolite near Minchinhampton. 
Ammonites Graciuis, Buckman. Pilate I, figs. 3, 3a. 
AmMONITES GRACILIS, Buckman. 1845. Geol. of Chelt., p. 104, t. 3, fig. 6. 
A. Testa discoided, compressa, anfractibus ovatis lateribus sub-complanatis, transversim 
30—40 costatis ; costis bi-trifurcatis vel intermediis, in dorsum continuis, apertura ovata, 
sub-sagittata. 
A discoidal, compressed, ribbed Ammonite, with six to eight oval, slowly creasing 
