100 
MR. E. C. BOUSFIELD ON THE 
The most beautiful of all the species of Dero ; but somewhat 
anomalous iu the position of the first dorsal bristles and in 
the possession of palpi. Only found among the fibrous buudles 
of the dead stems of Cyperus (in the Royal Botanic Gardens), 
which must be pulled apart to obtain the worms. 
Note. — The above descriptions all apply to the asexual forms 
only. A description of the sexual forms is reserved. 
Bibliography. 
1. Blainville. — Diet, des Sci. Nat. t. xxxiv. p. 131. 
, 2. Blainville.— Diet, des Sci. Nat. t. lvii. p. 499. 
3. Blainville. — Planches, Zool. Vers et Zooph. pi. xxiii. 
4. Bose. — Vers, i. p. 203. 
5. Bousfield. — Report Brit. Assoc. Adv. Sci. 1885, p. 1097- 
6. D’Udekem. — Bull. Ac. Roy. Brux. 1885, p. 549, f. 1. 
7. Duges. — Ann. Sci. Nat. ser. 2, t. viii. p. 31, pi. i. f. 24 & 25. 
8. Dujardin. — Ann. Sci. Nat. ser. 2, t. xi. p. 293, pi. vii. f. 9-12. 
9. Dutrochet. — Bull. Soc. Philom. Paris, 1819, ser. 3, p. 155. 
10. Fabricius. — Fauna Groenlandiea, p. 315, no. 269. 
11. Gervais. — Bull. Ac. Roy. Brux. 1838, p. 18. 
12. Grube. — Arch, fur Naturg. 1850, p. 353. 
13. Houghton. — Ann. & Mag. Nat. Hist. 3rd ser. vol. vi. p. 393. 
14. Johnston. — Catalogue of Brit. non-Parasit. Worms, p. 69. 
15. Leidy.- — American Naturalist, 1880, p. 421. 
16. Muller. — Zool. Danic. Prodr. no. 2651. 
17- Muller. — Verm. Terr, et Fluv. &c. pt. ii. p. 22. 
18. Muller. — VonWiirm. des suss. u. salz. Wass. p. 90, pi. v. 
19. CErsted. — Kroy. Nat. Tidssk. Bd. iv. 2, p. 133. 
20. Oken. — Lehrbuch der Naturg. iii. pt. 1, p. 363, pi. xi. f. 2. 
21. Pennant. — British Zoology, 1812, iv. p. 98. 
22. Perrier. — Arch, de Zool. exp. et gen. i. p. 65, pi. i. 
23. Rees’s Cyclopaedia. — Art. Nevis. 
24. Rosel. — Insecten-Belustigung, iii. p. 581. pi. xciii. 
25. Schmarda. — Neue wirbellose Thiere, ii. 9. 
26. Semper. — Arb. Zool. Inst. Wiirzb. 1877-78, p. 106, pi. iv. f. 16. 
27. Shaw.— Naturalist’s Miscellany, t. 452. 
28. Stewart. — Elements Brit. Zool. p. 391. 
29. Tauber. — Annulata Danica, i. p. 75. 
30. Turton. — British Fauna, p. 1 37- 
31. Vejdovsky. — Syst. u. Morph, der Oligocli. pp. 27 & 117- 
DESCRIPTION OF THE PLATES. 
Plate III. 
Fig. 1. Dero obtusa. The whole worm, enlarged from a photograph of the 
living object. 
2. A doi'sal view of the branchial area and processes of D. obtusa, drawn 
from life, x 75. 
3. The same. A copy of D'Udekem's original figure. 
