BY .TAS. P. HILL. 43 



garoos. Each communicates with a vagina, expanding into a 

 caecum with semitransparent walls and greatly surpassing the 

 uteri in size : the ctecum suddenly contract near the ora tincfe, to 

 form long and slender vaginal canals which converge but terminate 

 separately near the vulva. The urethra is of corresponding 

 length and tenuity; its orifice is near those of the vagina, the 

 urogenital passage having the least extent in this genus of 2Iar- 

 supialia." It ma}' be noted that in this account no mention is 

 made of a median vaginal apparatus. The second reference is 

 contained in a short paper by Alix (2) entitled " Sur les organes 

 de la parturition chez les Marsupiaux " and j^ublished in 1879. 

 After remarking that he had several times confirmed his pre%'ious 

 observation of the open condition of the median vaginal apparatus 

 in Halmaturus hennettii, he goes on to say, " mais d'autre part 

 je n'ai pas trouve de communication entre le vagin median et le 

 vestibule urogenital soit sur le Sarigue, soit sur le Peramele," a 

 statement which certainly shows that Alix had recognised the 

 presence of a median vagina in I'erameles. A t the time of 

 writing an account of the process of parturition in my paper on 

 the placentation of Pera7neles (3) I overlooked the above state- 

 ment of Alix and misinterpreted the median vaginal canals as 

 postei'ior prolongations of the uteri, an error which I trust will 

 be sutficiently corrected in the present communication. 



General Account of the Genital Organs. 



In Perameles the female genital organs consist of the following 

 parts — two ovaries, two oviducts, two uteri, two vaginas (includ- 

 ing the two lateral vaginal canals, with their casca and a median 

 A-aginal apparatus), a urogenital sinus containing the clitoris and 

 opening into the cloaca. The most distinctive feature of the 

 urogenital organs of this form consists in the fact that the lateral 

 vaginal canals and the urethra lie imbedded throuohout their 

 entire extent in an elongated mass of connective tissue (Plate i., 

 fig. 1, u s.), to which I gave in a previous paper the name of urino- 

 or better uro-genital strand, and which is developmentally none 

 other than the jiersistent genital cord of the foetus. Owing to 



