PROFESSOR OWEN ON THE BELEMNITE. 
79 
amination by the noble President gave the much-desired solution to the question ; the 
form of the muscular part of the mantle, the proportions of the arms, and the number, 
shape and disposition of the horny hooks, being identical in that specimen of theBe- 
lemnite with those in the beautiful one with the crown of uncinated tentacles formerly 
in Mr. Pratt’s cabinet, and now deposited, with the more perfect Belemnite from 
Lord Northampton’s collection, in the Hunterian Museum. 
I have more lately been favoured by Mr. Cunnington of Devizes with the tem- 
porary possession of the instructive specimen* of the Belemnites Owenii obtained 
from the same stratum and locality as the foregoing. It exhibits a considerable 
proportion of six of the cephalic arms ; one of them is three inches and a half in 
length, but not entire; a full inch of another is indicated or represented by the 
double series of hooks, in their natural relative position, there being ten pairs in this 
extent. 
The muscular tissue, forming the common base of the arms (A), has been preserved 
in a more compact mass than in Mr. Pratt’s specimen, but the arrangement of the 
fibres is distinguishable. A median fine groove may be traced along each of the best 
preserved arms, indicating the cavity in which the artery and nerve were lodged. 
From near the side of the common uniting base of the ordinary uncinated arms a 
long and narrow tract of fibrous matter {/c) bends down along the side of the head 
to the beginning of the mantle, becomes more slender than the cephalic arms, and 
is reflected, with an irregular twist, forwards again ; this is obviously the basal part of 
one of the long superadded tentacles. 
The most marked and peculiar character of the present specimen is seen in the 
part of the head immediately behind the base of the arms; at this part, imbedded 
in the usual grey remains of the muscular tissue, are two semicircular portions of a 
denser and darker greyish brown fibrous substance (/ l), obviously the same parts as 
those above described and referred to the eyes, in Mr. Pratt’s second speeimen-f-; 
the parts in question are regularly placed in reference to each other in the present 
specimen, being on the same transverse line, with their concavities towards each other, 
and their convexities turned outwards: each body is a line in breadth and does not 
diminish at either extremity, which is lost in or hidden by the surrounding muscular 
tissue : their structure is more minutely but more definitely fibrous than in the muscles, 
the fibres following the curve of the band. The parts in existing Cephalopods, which 
first suggest themselves for comparison with these, are, the beak, the cartilage of the 
head, the cornea or the crystalline lens. The position of the curved fibrous bodies is 
posterior to that in which the beak should be placed, agreeably with existing analo- 
gies ; the texture of the beak, also, in the Onychoteuthis is the same as that of the 
hooks, whilst that of the parts in question is very different from the black horny 
matter of the preserved hooks. The position of the parts in the present specimen, 
like that in Mr. Pratt’s, corresponds with that of the large sessile eyes, only that they 
* PI. VI. fig. l. t PI- V. 
