Miscellaneous. 
389 
outer chamber of certain Ammonites, as for exam})le, in A. Jasoni. 
In the phragniocone of the Belemnoteuthis the peristome is entire. 
Another interesting part of the structure of the Belemnite, not 
previously detected, is also shown in the same specimen, as well as 
in many other examples found in the Oxford clay near Trowbridge ; 
namely, a calcareous shelly periosteum or capsule, which invests the 
guard, and expands upwards into a horny sheath or receptacle, that 
surrounds the basal chamber of the phragmocone in which the viscera 
were probably contained. This receptacle was formerly supposed to 
originate from within the alveolus of the guard. Mr. Miller, many 
years ago, inferred the existence of a vascular integument around 
the guard from the meandring impressions of blood-vessels obser- 
vable on the surface of some specimens ; but the presence of a cal- 
careo-corneous capsule or sheath investing the guard, and expanding 
into a horny receptacle, has not till now been demonstrated. 
The author considers the facts described as proving that the ce- 
phalopod of the Belemnite was entirely distinct from the Belemno- 
teuthis ; and that the muscular mantle, cephalic arms, and other 
parts referred by Professor Owen to the former, exclusively belong 
to the latter genus. 
He concludes that the remains of at least three genera of naked 
Cephalopoda occur in the argillaceous deposits of the oolite in Wilt- 
shire ; namely, the first or true Calamary, with a horny dorsal gla- 
dius or pen ; the second, the Belemnoteuthis, or a decapod with unci- 
nated cephalic arms, ink-bag, pallial fins, and a corneo-calcareous 
phragmocone ; and the third, the Belemnite, which possessed a phrag- 
mocone having the apical part implanted in the cavity or alveolus of 
a guard or osselet, which in its original state resembled in substance 
the sepiostaire of the Cuttle-fish, but is generally found mineralized 
by calcareous spar ; and the peristome, possessing two or more elon- 
gated shelly processes ; both the guard and the phragmocone being 
invested with a corneo-calcareous capsule or receptacle. He observes, 
lastly, that the body and other soft parts of the cephalopod of the 
Belemnite are at present unknown. The author’s communication 
was illustrated by drawings, and accompanied by the specimens 
above described. 
MISCELLANEOUS. 
On a new genus and species of Fossil Ruminantia, Poebrotherium 
Wilsoni. By Joseph Leidy, M.D. 
Indirectly through Mr. J. S. Phillips and the influence of Dr. S. 
G. Morton, the Academy has become the depositary of a valuable 
and unique fossil, received through Dr. S. D. Culbertson of Cham- 
bersburg. Pa., from Mr. Joseph Culbertson. 
As first received, it consisted of a mass of argillaceous limestone, 
having one side of a cranium of an animal exposed to view, which, 
by the patience of Dr. T. A. Wilson, was relieved of its matrix ; and 
