1870.] DR. J. MURIE ON PHOCA GROENLANDICA, 607 
carefully executed drawings of the limb-myology of P. fetida. It 
is needless entering into detail ; but the result was that I detected no 
special arrangement in the muscles and tendinous distribution, both 
of the pectoral and pelvic extremities, which could satisfactorily 
account for the powers of grasp and differentiated raised creeping 
movements. 
In all three forms the flexor and extensor tendons agree in pat- 
tern and points of insertion. The small palmar and plantar muscles, 
including superficial and deep layers of interossei, are subdivided after 
the same fashion. As regards the shoulder and brachial muscles, 
there is no alteration in their implantation ; and hence no change in 
mode of action is apparent. If any specific difference exists, it must 
be in the volume and strength of the individual parts. But this is a 
factor which, unless very decided, the eye caunot well appreciate ; 
therefore to assume such is all that reasonably dare be ventured. 
Physiologically, it may be said there is more innervation ; but that 
can neither be seen, weighed, nor measured. 
I shall restrict my notes of the internal anatomy to a single spe- 
cimen, premising that the differences in the others examined by me 
were slight—chiefly relating to partial or deeper segmentation of 
the lungs and length of intestine. 
Meckel, in his ‘ Anat. Comp.,’ merely incidentally alludes to P. 
grenlandica, quoting the ‘ Naturhist. Bemerk. &c.,’ of Thienemann ; 
but I regret I have not been able to lay hands on this latter work. 
In a young male which died of congestion of the brain the following 
admeasurements were taken by me: — Extreme length =4 feet 3 inches. 
Of this, regionally, from the edge of the upper lip to the occiput was 
3 inches ; from the occiput to the tip of the tail 343 inches; from 
the occiput to the tip of the hind flipper 413 inches; the free part 
of the fore flipper 73 inches; and the free portion of the hind limb 
103 inches. 
The body weighed 41 lbs.; the skin when removed 6 lbs. 2 oz., 
and the viscera, including the tongue &c., 5 lbs. 2 oz. ; the brain 
with its membranes and blood-vessels (the latter much congested), 
8 ounces 2 drachms. 
In the specimen under consideration the heart presented a well- 
defined bifid extremity, the cleft being almost half an inch deep. 
The long diameter of the heart from root to apex was 3 inches, and 
the greatest transverse diameter near the base 32 inches. Others of 
the Greenland Seals did not show quite so deep an apical incision ; 
but in all, traces of separation at the point were discernible. I infer 
that in Phoca grenlandica, at a comparatively ripe age, nearly if not 
quite adult, this feetal stage of heart-cleft obtains. But latitude must 
be given to such a premise; for 1 have observed once in a young 
Porpoise, Phocena communis, with a length of body as great as the 
Seals, that a distinct division of the apex existed. In the Harp-seal 
this cardiac scission is very median in position, as in the Dugong 
and Manatee, and not so laterally placed as I found it in the Com- 
mon Porpoise. 
The right lung was entire or without divisionary lobules; but the 
Proc. Zoou. Soc.—1870, No. XLI. 
