THE SNAIL 



75 



Fig. 17 



A dissection of Helix aspersa from the dorsal surface. The roof of the mantle- 

 cavity has been cut through near the collar and thrown back ; the generative 

 organs are displayed on the left, and the alimentary tract on the right of the 

 figure, a/, albumen gland ; an, anus ; a^e, auricle ; bv, blood-vessels in 

 mantle ; c^, cerebral ganglion ; c r, crop ; dil, globular dilatation on sperma- 

 theca ; div, diveriiculum of spermatheca ; Ds, dart sac ; gl, glandular part 

 of excretory organ ; hd, hermaphrodite duct ; /?, flagellum of penis ; int> 

 intestine ; //, liver ; Mg, mucous glands ; od, oviducal portion of conjoined 

 genital duct ; ov, oviduct ; of, ovotestis ; P, penis ; pc, pericardium ; ph, 

 rynx ; R, rectum ; sal, salivary glands ; sd, duct of salivary gland ; spd, 



phar , 



spermiducal portion of conjoined genital duct ; 



ureter ; v, ventricle of heart ; vd, vas deferens. 



h> spermatheca ; ur, 



