PLATE 3. 



Fig. 1. Tethts CER^aNA Dall and Simpson. 



Fig. 1. Semidiagrammatic representation of tlie parieto-visceral ganglion complex as seen 

 from below. The contour of the organ of Bohadsch is represented by the dotted line, o B. The 

 anterior end of the animal is directed toward the upper margin of the Plate, the right side corre- 

 sponding to the left one of the figure; pl-par. c. pleuro-parietal connective; pl-o. c, pleuro-visceral 

 connective; p. g, right parietal ganglion; v. g, left visceral ganglion; pi, first parietal nerve, its 

 branch 1 a anastomosing with the branch 3/ of the third pedal nerve, 3 ped, its branch 1 h forming 

 the vulvar nerve; p2, second parietal, or osphracUo-ctenidial nerve; osp. g, the osphradium and its 

 ganglion, the fine terminal nerves passing to the ctenidium; v. 1, first visceral nerve, to the sperma- 

 totheca and its duct; v. 2, the second visceral nerve, $ a, its hepatic branch, 3 b, its main ramus, forking 

 to the rectum, r, and sijjhon, s, and the adjacent peritoneum; 2 c, its recurrent branch to the organ of 

 Bohadsch and anastomosing with 3 b, the branch of the third pedal nerve, 3 ped, to the same organ; 

 vS, the tliird visceral nerve, supplying the genital ganglion, g.g, and the reproductive tract; v. 4, the 

 fourth visceral nerve, branching into 4 a, to the ventricle, i; and the pericardium, p c, and 4 b, to the 

 auricle and pericardium, aii. pc, and to the kidney. A". 



Fig. 2-4. DoLABELLA AG.\ssizi, sp. nov. 



Fig. 2. A similar representation of the parieto-visceral ganglion complex. The abbreviations 

 used in Fig. 1 ajiply to this figure except that the second, third, and fourth visceral nerves arise 

 by a single trunk, i'. 2, which bifurcates into v. 2 a and v. 2 b; v. 2 a has relations similar to v. 2 

 of the preceding figure, save that its recurrent branch to the organ of Bohadsch forms an anastomosis 

 with a branch of the seventh, 7 ped, instead of the third pedal nerve; v. 2 b gives off a branch, 

 f bi, to the peritoneum of the spermatotheca, another, 2 b 3, to the genital ganglion complex, corres- 

 ponding to the third visceral nerve, v. 3, of the preceding figure, while the remainder, 2 b 4, repre- 

 senting the fourth visceral nerve, v. 4 of Fig. 1, is like it distributed to the heart, pericardium, and kidney. 



Fig. .3. Buccal ganglion complex as seen in dorsal view, i. e. the face in contact with the pharyn- 

 geal bulb. The outline of the connective-tissue sheaths of the ganglia and nerves is indicated by 

 the dotted Unes. The nerves are numbered serially b. 1 to b. 4, and are described fully in the 

 text,. The second nerve gives off a branch, c-b. con, which passes around the pharyngeal bulb to 

 the dorsal side and unites with the cerebral gangUa as the cerebro-buccal connective, {c-b. con, Plate 2 , 

 fig. 1); b 1 a, superficial branches of the first buccal nerve, h 1, shown in detail from the ventral surface 

 in fig. 4. X 8. 



Fig. 4. Ventral surface of the first buccal nerve, b 1, showing the origin of its superficial branches, 

 ; a. X 8. 



