ON THE ANATOMY OF THE NORTHERN BELUGA. 427 
The whalebone whales, in the matter of the aortic branches, resemble more 
closely of the arrangement met with in man. CaArTE and MACALISTER,* 
Turner,t Kwnox,t Escuricut,§ and Matm || all affirm the existence of a 
right innominate (which divides simply into a common carotid and a sub- 
clavian), as well as a left carotid and left subclavian, the three branches 
arising directly from the arch of the aorta. 
Contrasting Beluga with the two sections, it is seen to agree with the 
toothed whales in so far as regards the existence of two innominate trunks, but 
to differ from them in the absence of additional branches from the arch, and in 
the more regular distribution of the innominates by means of a subclavian and 
a common carotid—the latter apparently not existing in other toothed whales, 
with the doubtful exception of Delphinus phocena. From the whalebone 
whales it only differs in the fact that the common carotid and subclavian 
arteries on the left side do not come directly from the aorta, but from a left 
innominate trunk. Beluga, therefore, presents an arrangement which may 
be regarded as intermediate between the two sections. 
BRAIN AND ORGANS OF SENSE. 
Brain.—This organ we did not examine, as the state of the parts precluded 
the possibility of obtaining an accurate and reliable description of its structure. 
Fortunately, we possess a means of supplementing this deficiency in our own 
observations, in an excellent paper with accompanying drawings, by Dr HEr- 
BERT MaJor,‘ published in the last number of the “Journal of Anatomy and 
Physiology.” In it, in addition to the results of an elaborate investigation 
into its microscopic structure, with which we are not here immediately con- 
cerned, will be found the following description, by Professor Turner, of the 
cerebral convolutions in Beluga, drawn up from an examination of a photo- 
graph of the left hemisphere :— 
“A well-marked Sylvian fissure was present on the outer surface of the 
hemisphere. The convolutions were arranged around this fissure in four suc- 
cessive tiers, separated from each other by three well-defined fissures which 
extended generally in the antero-posterior direction. On the inner surface of 
the hemisphere the convolutions presented considerable complexity, but they 
were obviously arranged in relation to the direction of the corpus callosum, and 
extended in the antero-posterior direction from the frontal end of the cerebrum 
backwards and downwards. There was evidence of a division of the convoluted 
mass into three successive tiers by intermediate furrows extending antero- 
posteriorly above the corpus callosum and the convolutions of the middle tier 
*Lp. 245. . + XVII p. 229. p.e.4'008 
§ XXVIII. p. 104. || XXIX. q| XXX. p. 128. 
