PROFESSOR PETERS ON THE GENUS PECTINATOR. 407 
The thyroid cartilage (fig. 17, th) is narrowed in the middle, being here only 2 millims. 
long, has its superior border with three emarginations, and on each side a short process 
to meet the posterior horn of the hyoid bone. The cricoid cartilage (cr) is, as usual, 
much higher behind than in front. The thyroid glands (gi) are lateral, not connected 
with each other, flat and lengthened. 
The trachea (fig. 17, #r) has twenty-four cartilaginous half-rings, and divides into a 
shorter right and a longer left bronchus. It has a length of 19 millims. The left 
lung is divided into two lobes, each of them having a secondary incision on the middle 
of its anterior margin. The right lung is divided into four lobes. In shape the lungs 
correspond exactly with those of Chinchilla, and nearly also with those of Echinomys. 
Organs of Excretion and Generation. 
The kidneys (fig. 22,7) are, as in all Rodents, simple, and regularly bean-shaped: they 
are 15 millims. in length and 10 millims. in width. The right kidney is, for about half 
its length, in advance of the left. The suprarenal bodies(s.7) have a length of 6 millims. 
and a width of 2°5 millims. 
The generative organs resemble most those of Chinchilla. The testes (fig. 23, t, t) have 
their position on each side of the angularly bent penis. The tortuous vasa deferentia 
open into the urethra distinct from the ducts of the greatly developed vesicular glands. 
The prostatic glands terminate in the urethra where it begins to be covered with a 
fusiform muscular layer, which extends itself as far as the heart-shaped bulbus urethre. 
Immediately behind the bulbus are to be seen the large rounded Cowperian glands (Cp). 
the ducts of which are of moderate length’. The glans penis (g/) is very similar to that 
of Chinchilla, has a longitudinal slit on its underside, and a terminal folded point covered 
by two small lobes. The ossicle sustaining the glans has a length of 11 millims. 
In the female (fig. 22) the two uteri are distinct, except at their end, where they 
are externally united for about 3 millims., each of them, however, opening separately 
into the vagina. According to Professor Owen’s observations, an exactly similar form 
of the female organs is to be found in Lagostomus*. The clitoris has the same form, 
only on a smaller scale, as the penis of the male, and is perforated by the urethra, which, 
therefore, opens quite separate from the vagina. 
According to Dr. v. Heuglin, the female Pectinator is pregnant in the month of 
September or October, and contains then two or three foetus. This corresponds with the 
small number of teats, of which, as I have mentioned already, there is only one on each 
side of the body. 
* Professor Gegenbaur (Grundziige der yergleichenden Anatomie, Leipzig, 1870, p. 883) names these glands, 
which evidently correspond to the Cowperian glands in man, “Tyson’sche Driisen,” and gives the name of 
Cowperian glands to the prostatic glands. 
* Proc. Zool. Soc. London, 1839, p. 177. 
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