1870. ] DR. J. MURIE ON PHOCA GRENLANDICA. 605 
brought the fact before our eyes. These two kinds of land-motion, 
abdominal and quadriplantigrade, are all, to my knowledge, that 
“have been recognized among the family of Phocide. 
Nevertheless a third sort of land-movement, intermediate between 
those mentioned, is the habit of certain Phocine species ; and to call 
attention to this is the chief object of the present paper. 
A few Greenland Seals (Phoca grenlandica, Mill.) were purchased 
by the Society in May 1869; and then for the first time this species 
was exhibited in the Gardens to the public. To most observers, 
unacquainted with the varieties of Seals, these animals exhibited 
nothing to distinguish them from the Common Seal of our coast, if 
seen with the skin wet. But when dry they did show, even to the 
unpractised eye, a difference, in their whiter coats; and, instead of 
minute regular dark spots, irregular bands and slashes of a black hue 
intermingled with sparse circular spots arrested the attention. In 
some of the specimens, barely adult, at least not old, the broad loin- 
patch of a deep blackish shade was moderately developed—this 
being the marked external characteristic of the species, and, in fact, 
from which the popular names of Harp-seal and Saddle-back are 
derived. 
Having given attention to the modification of walk and somewhat 
vermiform land-action betwixt the Otary, Morse, and the Common 
Seal, I was both surprised and delighted to find that the Saddle-back 
at times moved on the ground quite differently from either. A good 
idea of the difference of attitude of the two latter is best gathered 
from the illustration, Plate XXXII. It represents, from sketches 
taken of the live P. greenlandica, one of these animals (that in the 
foreground) moving in its usual manner, after the fashion of the 
-Common Seal—that is, belly-wise, the fore limbs tucked towards the 
chest, the hind legs thrust backwards and in apposition. 
The remaining four figures, however, vary considerably in attitude ; 
and each is characteristic of what I have oft witnessed in the Harp- 
seal, and I may add the “‘ Bladder-nose”’ (Cystophora cristata), lately 
added to the collection, but never have seen in the Common and the 
Ringed Seal (P. fwtida). The Greenland Seal, in fact, very often uses 
its fore limbs, placing these on the ground in a semigrasping manner, 
and by an alternate use of them drags its body along. The hind 
legs meantime are either trailed behind slightly apart, or with op- 
posed plantar surfaces slightly raised and shot stiffly behind. On 
uneven ground, or in attempting to climb, a peculiar lateral wrig- 
gling movement is made; and at such times, besides alternate pal- 
mar action, the body and the hind legs describe a sinuous semi- 
spiral or wave track, as shown in the figure to the left. 
Dr. Pettigrew, in his admirable memoir on the mechanism of 
flight*, has carefully analyzed the swimming of the Seal, Sea-bear, 
and Walrus; and in my papers on the anatomy of the two latter I 
have alluded to their movements on land ; so that further comparison 
here is unnecessary. 
To the theory of evolution the matter I have been dilating on is 
* Trans. Linn. Soe. vol. xxvi. (1867) p. 207. 
Proc. Zoou. Soc.—1870, No. XL. 
