ON THE ANATOMY OF THE NORTHERN BELUGA. 429 
the organ. The same arrangement holds good in Beluga. In Lagenorhynchus * 
Dr Morte noticed the coalescence of several of the renal lobules in contra-dis- 
tinction to the isolated character of these in Globiceps and other species. But 
such was not the case in Beluga. Asa rule, the urinary bladder seems to be 
of small size in the cetacea, the only exception being that of Zyphiorrynchus, in 
which, according to BURMEISTER,* it is of large size. In respect of the size and 
form of this viscus, Beluga agrees with the majority of the cetacea. 
: 
FEMALE GENERATIVE ORGANS. 
Vulva.—The vulva is represented by an elliptical fissure 5 inches in length, 
the posterior extremity of which is situated three-fourths of an inch in front of 
the anus. The integument surrounding the former is smooth and elevated, so 
as to form two well-marked lateral pads representing the labia majora. Lying 
in the anterior commissure of the vulva, and to some extent concealed by the 
labia majora, are two well-defined folds of mucous membrane—the labia minora. 
Each measures 1 inch in length, and together they enclose an elliptical space 
in which lies the clitoris. The nymphe are quite continuous with one another 
behind the clitoris, and form a prepuce for that body ; whilst in front of it they 
are lost in the anterior commissure of the vulva, where they become continuous 
with the inner surfaces of the labia majora. The body of the clitoris, measur- 
ing one-fourth of an inch in length, is conical in form, and somewhat flattened 
from side to side. The nymphe unite with it and with each other along its 
posterior border. 
The external genital organs do not appear to vary much in female 
cetaceans. Alike in the toothed and in the whalebone whales, there is a well- 
developed clitoris, together with labia majora and minora. With regard 
to the latter, Dr Munir { states that in Globiocephalus they form ‘“ two promi- 
nent folds of mucous membrane, each an inch in length, which lie within the 
anterior pudendal commissure, and slightly converge as they pass backwards.” 
This arrangement appears to indicate an approach to that described above in 
Beluga, in which the labia minora unite with one another behind the clitoris to 
form the prepuce. In Balenoptera Sibbaldii, Professor TuRNER § observed that 
the labia minora “ passed backward external to the meatus urinarius ;” whereas 
in Beluga they become continuous with one another in front of that orifice. 
Vagina.—The vagina measures 8 inches in length and 25 in breadth when 
flattened. Its superior or dorsal surface is invested by peritoneum to within 
two inches of its posterior extremity, at which spot the serous membrane is 
reflected to the rectum. The inferior or ventral surface is also covered by peri- 
toneum as far back as opposite the vesical extremities of the ureters, whence it is 
> V.-p.'149. + XLL p. 97. eK spi 285: § XVIL p. 201, 
VOL. XXIX. PART I, 58 
