BY JAS. P. HILL. 525 



an internal septum. A distinct cloaca is present. The cloacal 

 opening is of characteristic form, being long, narrow and spout- 

 like (fig. 5). A cloacal sphincter muscle is not present. A pair 

 of large anal glands open far back into the cloaca. 



IV. Notes on the Female Urogenital Organs of Acrobates 

 PTGMjEUS and Petaurus drevweps. 



The female organs of Acrobates have already been shortly 

 described by Owen,* whose observations I in the main confirm, 

 and extend. The following notes are derived from an examina- 

 tion of a series of serial sections through the organs of a pregnant 

 female, with shrivelled blastodermic vesicles in the uteri and 

 with three 2 cm. young in the pouch. 



The two uteri pass back side by side and posteriorly gradually 

 contract to form the uterine necks, which after a quite short free 

 course enter the connective tissue between the forwardly projecting 

 portions of the lateral vaginal canals, to open each by a medianly 

 situated aperture on a slight papilla, into the corresponding 

 median vagina. As Owen described, two median vaginae are 

 present. They are separated by a common partition wall over 

 by far the greater portion of their extent, but in my specimen, 

 unlike Owen's, the septum disappears posteriorly, so that there is 

 here a quite short common median vagina recalling the condition 

 in the multiparous Perameles. This ends blindly in the con- 

 nective tissue between the lateral vagina? about -6 mm. above the 

 anterior end of the urogenital sinus. Although remains of a 

 pseudo-vaginal passage are not certainly recognisable, I am 

 inclined to believe that such will be found to occur at parturition. 

 The lateral vaginal canals, as Owen describes, pass forwards 

 alongside, and external to, the uterine necks and then bend out- 

 wards, " forming a curve like the handles of a vase." They then 

 converge and pass back with the urethra and median vagina? in 



* Owen, E. " On the Generation of the Marsupial Animals, d'C." Phil 

 Trans. 1834. 





