702 



ANATOMY OF VERTEBRATES. 



by a vertical fissure, and inclosed above and at the sides by a 

 crescentic prepuce. The urethra is consequently of unusual 

 length in these small Quadrumana, as it is in Moles and Shrews. 

 When the cerebrum begins to show deep and definable gyrations 

 a higher type of female organs is indicated. The uterus is differ- 

 entiated from the vagina by an os tincse in the Aye-aye, and the 

 clitoris is distinct from the urethra. Moreover the vulva opens 



at about one and a half 

 inch distance from the 

 vent. The uterine horns 

 are relatively longer than 

 in most other Lemuridce. 

 The os tincae appears trilo- 

 bate through fission of the 

 anterior valve or ( lip.' 

 The vagina shows the 

 usual provision for dilata- 

 tion in the longitudinal 

 folds. The urethral orifice 

 defines a urogenital tract 

 about one-third the length 

 of the vagina : the prepu- 

 tium clitoridis opens by a 

 transverse crescentic fossa 

 anterior to the urogenital 

 outlet : the crura clitoridis 

 embrace the urogenital 

 passage before uniting, on t 

 its fore wall, into the body 

 of the clitoris : the glans 

 is subbilobate. 1 



In the Mongoose and 

 other species of true Le- 

 mur, the uterus communicates with the vagina upon a distinct 

 valvular prominence or os tincaa ; but the clitoris is situated more 

 within the verge of the vulva than in Chiromys, and is perforated 

 by the urethra. The rugae of the vagina are well developed, and 

 are of two kinds ; the stronger ones are longitudinal, in the inter- 

 spaces of which are smaller transverse or oblique folds: these 

 assume a penniform arrangement near the outlet. The clitoris is 

 inclosed in a large and thick internally plicated prepuce. The 

 external labia are continued from the dorsum of the clitoris ; within 

 1 ccxin'. p. 97, tab. 3, figs. 2 and 3, 



Rectum, vagina and urethra, Stenops tardigradus. lxix'. 



