THE ANATOMY OF SOFT-BILLED TURTLES. 405 
Cinosternide, but not more so perhaps than that of some of 
the aged Chelydride. 
The generative organs of both sexes possess many points of 
interest, and many striking peculiarities of structure. The oviducts 
of the female are greatly extended, and each possesses a distinct 
sphincter near its prominent orifice. Moreover, the distal or in- 
ferior third is abruptly narrowed into a small duct—the analogue, 
perhaps, of the Fallopian ducts of higher Vertebrates; but the 
remainder corresponds in relative position and value to the uteri of 
of Marsupials and Monotremes. The lining membranes of these 
organs is remarkably white and smooth, and with the exception of 
perhaps two or three minute and isolated mucous glands presents 
neither crypt nor follicle—nothing apparently to provide for the 
covering of the eggs of the reptile; yet it would seem, in spite of 
appearances to the contrary, that this mucous lining must never- 
theless possess the power of rapidly secreting calcareous material. 
The ovaries proper average from three to five inches in length, and 
appear merely as the thickened edge of the mesenteric membrane 
with which they are invested, and which suspends them in proper 
position and connects them with the kidneys and other viscera. 
They are scarcely more dense than those of the Ranide, and the 
ova are produced only in a narrow strip of the outer part of the 
meso-ovarium. ~ 
The male organ is usually represented by comparative anatomists 
as large, both in structure and in form, and resembling closely 
what obtains in the Struthionide, particularly the male Struthio 
camelus. ‘The singular intricacy of the structure, while it presents 
an analogy to some of the Marsupials, as the Echidne and Mono- 
tremes, in which the same organ is likewise quadrifid, more nearly 
resembles the double bifurcated organ of the Crotalide and 
Viperine, yet is even more complicated than in these reptiles. 
This hardly tallies with Professor Owen’s supposition that the bifid 
extremity of the male organ is an adaptive structure corresponding 
to the bilateral or double uterus of females, and having reference 
to multiparous reproduction. If such were the case, we should 
reasonably expect to find the female Aspidonectes possessed of a 
quadruple uterus; whereas, as already shown, it is but a double 
organ. The cloacal orifice, which is located half an inch or more 
from the extremity of the somewhat elongated tail, would seem to 
suggest an explanation of the length of the latter organ, which 
