PARKER.— Notes on Balsenoptera musculus ? 11 
The foregoing observations show that the present specimen agrees with 
Balenoptera musculus in every essential respect except the characters of the 
nasals and of the sternum. Without knowing anything of the external 
characters I think it would be extremely injudieious to consider the 
peculiarities of these bones as having anything more than a varietal im- 
portance. Indeed one would have no hesitation in definitely referring the 
Nelson skeleton to the same species as the common Rorqual of the 
northern hemisphere, but for the fact that considerable confusion seems to 
exist as to the external eharaeters of the Southern Fin-whales. 
In a recent article* Professor Flower remarks: “There are certainly 
four quite distinct modifications of this genus [ Balenoptera] , represented by 
the two just mentioned [B. sibbaldit and B. rostrata], and by B. musculus 
and B. borealis, all inhabitants of British seas; but the question whether 
almost identical forms found in the Southern or Pacific Oceans are to be 
regarded as specifically identical or as distinct, awaits the result of future 
researches." 
Gray! describes a species, Physalus? (Balenoptera) australis, Desmou- 
lins, distinguished by having the dorsal fin over the male organ as in 
Megaptera. The same author] admits a species, PA. antarcticus, founded 
entirely upon some yellowish-white baleen imported to England from New 
Zealand. ; 
Hector|| calls the Port Underwood skeleton Physalus australis in the text 
of his paper, while in the description of plates it is referred to as Ph. 
antarcticus. Taking into consideration that it is an adult skeleton, it agrees 
in all essential respects with the Nelson specimen, at least as far as I can 
judge from the brief description, except in the form of the sternum, which, 
as stated above, is broader than long. 
It was upon the Port Underwood skeleton that Gray§ founded his new 
genus and species Stenobalena xanthogaster ** peculiar for the shortness of its 
pectoral fins, its plaited belly, and low recurved and pointed fin placed over 
the vent, and very peculiar among all whalebone-whales for the form of its 
bladebone.” As a matter of fact, I find on referring to Hector’s paper that 
the pectoral fin was only a little less than one-eighth the total length of the 
body (body 70 feet, bones of fore-limb 8 feet 6 inches), which appears to be 
the usual proportion for B. musculus: the plaited ventral surface also obtains 
in that species, in which, further, the dorsal fin is over the vent. As for 
the scapula, all Dr. Gray had to depend on was an extremely rough sketch 
taken from the fresh bone before the cartilage was removed, and apparently 
* Encyclopedia Britannica, 9 ed., vol. xv., art. Mammalia. 1 Loe. cit., p. 164. 
1 Catalogue of Seals and Whales, p. 161. || Trans. N.Z. Inst., vol. vii., p. 251. 
$ Note to paper by Hector, Ann. and Mag. N.H., 4 ser., vol. xiv., 1874, p. 304. 
