MAMMALIA. 
25 
lections in which they are contained. Bull. Ac. Roy. Belg. 
XXV. pp. 88-125. 
Prof. VAN Beneden has made researches on the pelvis of 
Cetaceans; it is present in all Cetaceans, consisting of a single 
hone on each side, representing the ischium. There is no 
median (pubic) bone. In the Right Whales and Megaptera a 
completely ossified rudimentary femur is added, remaining car- 
tilaginous in some BalcEnopterce. Balc^na mysticetus has a car- 
tilaginous tibia, besides the osseous femur. L. c. xxv. pp. 428- 
433. 
SMr. R. Brown has published his observations on the Ceta- 
ceans frequenting Davis Strait and BaffiiPs Bay in Proc. Zool. 
Soc. 1868, pp. 533-556; a great part of the paper is devoted to 
Balcena mysticetus. 
Prof. Burmeister enumerates eight species of Dolphins, two 
of Catodonts, and four of Balienidse as found in the seas off the 
coasts of the Argentine Republic. An. Mus. Buen. Ayres, 1868, 
pp. 301- 311. 
^Balcrna. Prof, van Bonodon fixes the googrnpliicnl distribution of the 
five species which ho regards as well established thus: — 1. B. mysticetus is 
restricted to the Glacial Sea, extending southwards into Baffin’s Bay, and 
along the Siberian and Kamtschatkan coasts into the sea of Ochotsk ; it does 
not extend as far as the north of Iceland. 2. B. biscayensis, the truly Atlantic 
species, extends from the coasts of temperate North America to Europe, 
reaching as far northwards as Iceland. 3. B. jo2)onica, the species of the 
North Pacific, from China and Japan to the coast of North America, between 
40° and N. lat. 4. B. australis, the species of the South Atlantic, from 
the coast of South America, 35° and 50° S. lat., to South Africa. 5. B. an- 
tipodarum, the species of the South Pacific, extends in a rather narrow belt 
from New Zealand to the southern extremity of the American continent. 
The paper is published in Bull. Ac. Roy. Belg. 1868, xxv. pp. 9-21 (and also 
in Ann. Sc. Nat. ix. pp. 43-52), and illustrated by a map. 
\) Dr. Guay has reviewed this paper, Ann. & Mag. Nat. Hist. 1868, i. 
pp. 242-247 ; having collected the positive evidence we possess of the geo- 
graphical distribution of the species of Right Whales, he comes to the con- 
clusion that the distribution as propounded by Prof. Van Beneden is founded 
on a theory, and not sufficiently proved by facts. 
Prof. VAN Beneden has replied to the principal points of Dr. Gray’s 
critical remarks. Bull. Ac. Roy. Belg. xxvi. p. 7. He states, — 1, that the 
Right Whale of the Southern Indian Ocean is not sufficiently known to be 
admitted into the system ; 2, that there is enough evidence to show that 
there are two species in the North Pacific, and that one of them is B. mys^ 
ticetus', 3, that the form and arrangement of the first ribs is subject to varia- 
tions on the two sides of the same individual, and, therefore, that this is not 
a character by which B. cisarctica (Cope) can be distinguished from B. bis- 
cayensis. The author figures two instances of asymmetry of the anterior 
ribs. 
4 Balcena mysticetus. Prof, van Beneden has found the so-called ‘‘ Bonnet ” 
in a foetus ; he also describes the tongue, /. c. xxvi. pp. 186-196. 
