390 MR. W. H. FLOWER ON THE SKELETONS OF WHALES [Nov. 8, 
each other to warrant their division into subfamilies; but they con- 
stitute two tolerably well-marked genera (Balena, Linn., pars, and 
Eubalena, Gray), which present the following among other less- 
marked distinctive characters :— 
(1.) Balena. Total number of vertebrae 54. Pairs of ribs 13. 
Head more than one-third of the total length of the body. Nasal 
bones long and narrow (fig. 1). Orbital processes of frontals much 
elongated, sloping backwards, and very little dilated at their extre- 
mity. Cervical vertebre all ankylosed. Baleen-plates very long, 
and narrow at the base. 
Type species B. mysticetus, Linn., at present the only one 
known. The most specialized in structure of all the Whales. 
(2.) Eubalena*. Total number of vertebree 57-58. Pairs of ribs 
15. Head less than one-third of the total length of the body. 
Fig. 3. 
Fig. 2. 
Upper surface of nasal bones of Whales of different genera, ,th nat. size. 
Fig. 1. Balena mysticetus. Mus. Roy. Coll. Surg. 
. Eubalena australis?, Mus. Leyden. 
. Megaptera longimana. Mus. Brussels. 
. Physalus antiquorum, Mus. Roy. Coll. Surg. 
. Sibbaldius schlegelit. Mus. Leyden. 
. Balenoptera rostrata. Mus. Roy. Coll. Surg. 
> Ory Cob 
* The very few skeletons of members of this genus in Europe present consi- 
derable discrepancies, which have never been satisfactorily investigated. As the 
Leyden specimens are the only ones I have seen, the above characters are taken 
from them; but I have now reason to believe that they do not belong to £. aus- 
tralis(Desm.). Dr. Gray, in a recent paper (Ann. and Mag. Nat. Hist. Noy. 1864), 
makes three genera of the Southern Whales—Eubalena, Hunterus, and Caperea. 
