THE SPERM WHALES, GIANT AND PYGMY. 735 
As may be supposed, animals from places so widely dis- 
tant have furnished the bases for different specific names, and 
after various fluctuations of opinion, in the last general com 
pleted work on the cetaceans—that by Dr. Gray already 
referred to—three authenticated and four doubtful species 
of true Physeterine are admitted, exclusive of the nominal 
Physeter tursio. The three considered established by him 
are Catodon macrocephalus, Catodon australis, and Mega- 
neuron Krefftii; the four "species wanting further confirma- 
tion” are the Pacific sperm-whale (Catodon Colneti Gray), 
the South African sperm-whale (Catodon macrocephalus A. 
Smith), the Indian sperm-whale (Catodon macrocephalus 
Blyth), and the South Sea sperm-whale (Physeter polycy- 
phus Quoy and Gaimard). | 
Professor Flower, after an elaborate comparison of skele- 
tons of Physeter from the British waters and from the 
Tasmanian seas (the home of P. australis), arrived at the 
conclusion that the apparent differences of P. australis, com- 
pared with P. macrocephalus, were the characters of imma- 
turity or the result of error in the identification of parts, and 
"putting aside these distinctive characters as valueless, there 
is not one other presenting any approach to a specifie dis- 
tinction pointed out throughout the whole memoir by Wall," 
and he himself has been unable to find any specific differ- 
ences between the Northern Atlantic and Southern Pacific 
forms; he, however, is careful to remark that he does not 
"deny the possibility of their being specifically distinct," and 
very appropriately adds that “similarity of osteological char- 
acters does not prove unity of species." But until such can 
be defined, specific names would only mislead. 
As to the "species wanting farther confirmation," it is suf- 
ficient that Dr. Gray ranks them in that category. 
One other name only needs notice, the Meganeuron 
Kreftii Gray, founded on cervical vertebre ; the atlas cer- 
tainly differs considerably from those of the Physeter macro- 
cephalus hitherto made known. Mr. Krefft, however, who 
