182 ON THE ANATOMY OF THE KOALA. 



system in the male. In their essential points they differ in no important 

 respect from those of the Wombat *. 



P. Z.S. 1881, The ovaries are rounded ovals in shape, considerably depressed, and 

 p. 189. measuring about -45 inch along their greatest extent. They are cut up 

 by three or four sinuous fissures ; each of these lobes is further subdivided 

 into ovisacs, which are of large size for a Mammal, though nothing like 

 so big as the large ones figured by Prof. Owen in Phascolomys. The 

 ovaries are enveloped to some extent by the fimbriated ends of the Fallo- 

 pian tubes, and are enclosed, in common with these, in pouches of delicate 

 peritoneum. The fimbriated ends of the oviducts are attached narrowly 

 to the posterior part of the ovary ; they extend hence for about O5 inch 

 to the ostium abdominal*. 



The Fallopian tubes are a little bent, and are of small calibre, passing 

 gradually into the larger, somewhat fusiform uteri, which, as usual in 

 the Marsupials, are quite separate from each other; muscular, thick- 

 walled, and nearly straight, these open on a prominent, somewhat com- 

 pressed nipple-like eminence, forming the os tincce, by a small pore. The 

 total length of the Fallopian tubes and uteri is about 1*3 inch from the 

 ostium at the commencement of the former. The vagina3 are also two 

 in number, each being bent outwards in a simple curve, and not com- 

 municating with its fellow at any point. The lower part of each vagina 

 is thick-walled, with but a small central cavity which opens into the 

 urino-genital sinus by a small pore, O2 inch above the opening of the 

 vesical urethra. Above they are thin-walled; and from the internal 

 side is developed a blind cul-de-sac, also thin-walled, communicating only 

 with the vagina of its own side and the corresponding uterus, there 

 being a median septum between the two culs-de-sac. No opening from 

 the latter into the urino-genital sinus exists in either specimen I have 

 examined. From the os tincce there is prolonged downwards on each 

 side a slightly elevated fold of the mucous membrane, which separates off 

 the vagina proper from the more medianly placed cul-de-sac. 



Both vaginae and culs-de-sac are lined by smooth mucous membrane, 

 with slight longitudinal rugae. The two uteri, as well as the vaginas and 

 their appendices, are united together by peritoneum. The two ureters 

 penetrate this to open into the neck of the bladder, beyond the termina- 

 tion of the vaginal culs-de-sac. The length of the vaginae is about 0*65 

 inch, measured in a straight line ; that of the culs-de-sac about 0*45 inch. 



The urino-genital sinus is a tube, with moderately thick walls and 

 longitudinally plicated mucous membrane, of 1-3 inch in length. It 

 communicates below by a considerable aperture with the rectum, and the 



* For description of these see Owen, P. Z. S. 1836, p. 52, and Anat. Vert. iii. p. 680 

 et seq. 



