410 



CHELONIA. 



tached to its ventral wall, a large copulatory organ, and receives 

 the opening of the bladder. 



In both sexes the urinary and generative ducts open separately 

 into the neck of the bladder, which must be regarded as 

 a urinogenital sinus. 



The penis,* which is a development oflthe ventral wall of the cloaca, 

 ends freely in a glans penis, and is marked on its dorsal side by a groove 



which contains in its front end 

 the opening of the bladder (Fig. 

 230). The penis consists of a 

 fibrous body (Fig. 231), which 

 bifurcates in front and is attach- 

 ed, not to the pelvis, but to 

 one of the dorsal vertebrae, and 

 of some erectile tissue (Fig. 231) 

 round the groove and in the 

 glans. In the female there is 

 an organ, the clitoris, similar to 

 the penis but less developed. 



Peritoneal canals t are pre- 

 sent. Their abdominal openings 

 are placed in a recess of the per- 

 itoneum close to the neck of the 

 bladder. They lie in the penis 

 near the groove, and either end 

 blindly in the glans or open into 

 the cloaca at the base of the 

 glans. In the female they run 

 in the ventral wall of the cloaca 

 and open near the glans of the 

 clitoris. 



The suprarenal bodies are two 

 rather long, yellow bodies on 

 the inner surface of the kidneys. 



FlO. 230. Cloaca and urinogenital organs 

 Chelydra serpentina (from Gegenbaur). The 

 cloaca is laid open from the dorsal side. c,c' 

 blind sacs of cloaca ; cl cloaca ; e epididymis 

 and vasdeferens ; p penis ; r kidneys ; r e rectum; 

 groove on penis ; t testis ; u ureter ; vg 

 cloacal opening of urinogenital sinus ( bladder) ; 

 v bladder. 



The eyes are contained in 

 closed orbits and possess 

 upper and lower lids and 

 a nictitating membrane. 



There is no pec ten. Lacrymal and harderian glands are present. 



There is always a tympanic cavity with a wide eustachian 



tube not enclosed in bone, a long columella auris, and a tympanic 



membrane visible externally. 



Vascular system. The sinus venosus is distinct and receives 



* Boas, Morph. Jahrb., 17, 1891, p. 

 178, p. 5. 

 f Gadow, I.e. 



271. Gadow, Phil. Trans, 1887, 



