THE LIZARD. 171 



189. The aperture of the urinary bladder in the ventral 

 "wall of the anterior division of the cloaca. 



In the male .■— 



190. The vasa deferentia (Fig. 41, v.d), convoluted 

 tubes, continuous with the epididymes in front, and passing 

 backwards to the dorsal wall of the cloaca. 



191. The urinogenital apertures {u.g), minute aper- 

 tures each on the apex of a small papilla on the dorsal wall 

 of the posterior division of the cloaca. 



192. By turning aside the cloaca the ureters maybe seen 

 as delicate tubes situated between the pelvic and renal veins, 

 and uniting posteriorly with the vasa deferentia. 



193. The copulatory organs (/), vascular eversible 

 sacs, lying on the ventral side of the tail, immediately 

 beneath the skin, and opening into the posterior part of the 

 cloaca. When everted each is seen to be a somewhat 

 cylindrical body, with a dilated and bifid apex. 



In the female : — 



194. The paired apertures of the oviducts (Fig. 42, od") 

 in the dorsal wall of the hinder division of the cloaca, just 

 posterior to the dividing ridge : anteriorly the oviducts open 

 into the coelome by wide apertures (od'). 



195. The apertures of the ureters (ur), small oblique 

 slits in the dorsal wall of the cloaca, a little posterior to the 

 oviducal apertures. 



196. The ureters themselves are situated as in the male 



(§ 192)- 



XXII. Lay open the pericardium and observe 



197. The ventricle (Figs. 40 and 43, v), a fleshy conical 

 structure, having its pointed apex directed backwards and 

 connected to the pericardium by a fine Hgament. 



198. The right (r.au) and left (l.au) auricles, thin- 



