THE UROGENITAL SYSTEM. 273 



M. urethralis (/"). — This consists of fibres surrounding the 

 cranial part of the urogenital sinus and the caudal parts of the 

 vagina and neck of the bladder. 



Origin partly on the caudal part of the symphysis of the 

 ischium, partly from the ventral surface of the urogenital sinus, 

 where the fibres are attached to the corpora cavernosa clitoridis. 

 The fibres pass dorsad over the surface of the sinus, and over 

 the surface of the union of the vagina and neck of the bladder, 

 to be inserted into the sides of the vagina and the dorsal surface 

 of the urogenital sinus. 



