PLATE VIII. 



Fig- 35- Parieto-visceral ganglia and nerves of Tethys cervina 

 Dall and Simpson. The contours of the Organ of 

 Bohadsch, o. B., and the pericardial cavity, per. c., are 

 indicated in dotted lines, that of the reproductive sys- 

 tem in light lines and unshaded. The anterior end of 

 the animal is directed toward the upper side of the 

 plate, the right of the animal corresponds to the left of 

 the plate, the preparation being drawn in ventral view. 

 r. pi. par. con., right pleuro-parietal connective ; /. p. v. 

 con., left pleuro-visceral connective; par. v. g., the 

 parieto-visceral ganglion complex, the ventral, or vis- 

 ceral moiety concealing the upper parietal portion; 

 r. p. L, vulvar nerve of right parietal ganglion, bifurcat- 

 ing into ia., which anastomoses with a branch of the 

 third pedal nerve, 3 ped., and ib., the vulvar nerve 

 proper; r. p. 2, osphradio-ctenidial nerve; osp. g., os- 

 phradial ganglion ; o. g. I., nerve to mantle ; ct . g., cteni- 

 dial ganglion ; /. v. 2., second nerve of left visceral gang- 

 lion ; 20,., its hepatic branch ; 2b., its main branch forking 

 to siphon and anus ; sc., its recurrent branch to the peri- 

 toneum and the organ of Bo j anus, anastomosing beyond 

 the latter with a branch of the third pedal nerve; 3 

 ped., of the right side; 2d., its branch to the posterior 

 peritoneum, etc.; 2e., the branch to the organ of Bo- 

 janus; /. v. 3., third nerve of left visceral ganglion, 

 supplying g. g., the genital ganglion, and dividing into 

 v. ja., and v. 3b., to the small hermaphroditic duct and 

 ovotestis, and to the dorsal body wall respectively, other 

 delicate minor branches noted in the text not being rep- 

 resented. /. v. 4., fourth nerve of left visceral ganglion, 

 4a. its branch to ventricle and pericardium, qb. its 

 branch to kidney, pericardium and auricle. 3 ped., 

 main trunk of third pedal nerve of right side, bifurcat- 

 ing into 3a and $b. $a gives off 30 to the organ of 

 Bohadsch, and j/, which anastomoses with a branch 

 of the vulvar nerve, la, and is distributed to the muscles 

 of the body wall. 56 sends off 3d to the right retractor 



