278 J. T. CUNNINGHAM. 



Fig. 17. — Pseudbaemal system of Trophonia plumosa, as seen on dis- 

 section, d. v. Dorsal vessel, v. v. Ventral vessel, hi. Heart, int. Intes- 

 tine, o. p. Suboesophageal pouch, ov. Ovary. 



Fig. 18. — Vertical longitudinal section through the heart and adjacent part 

 of the intestine of Trophonia plumosa. bl. Blood or pseudha:mal fluid. 

 c. b. Tubes of the cardiac body ; some with an open lumen, others full of 

 transparent cells, ep. Epithelium of the intestine. A, Zeiss, oc. 2. 



Fig. 19. — A single tube of the cardiac body shown in previous figure, 

 More highly magnified. Shows the nucleated cells lining the wall and a large 

 central lumen. E, Zeiss, oc. 2. 



Fig. 20. — Transverse section of heart of Flabelligera affinis, showing 

 cardiac body in the interior. A, Zeiss, oc. 2. 



Fig. 21. — Transverse section of dorsal vessel and contained cardiac body in 

 Cirratulus cirratus. c. b., bl., as before. E, Zeiss, oc. 2. 



Fig. 22. — Transverse section of ventral nerve-cords of Siglion boa, from 

 middle of body, interganglionic region, n. co. Nerve cord. n.c. Neural-canal. 

 *. n. Supraneural connective tissue, ed. Epidermis, ct. Cuticle. 



Fig. 23. — Transverse section of nerve-cords of Nerine coniocephala. 

 n. co. y n. c, as before. 



Fig. 24. — Trausverse section from same series as preceding figure, near the 

 anterior end of the animal. Letters as before. C C, Zeiss, oc. 3. 



Fig. 25. — Transverse section of Magelona papillicornis. n.c, as 

 before. 



Fig. 26. — Transverse section of Sabellaria apinulosa, middle of the 

 body. n. co. Nerve cord, with its neural canal. 



