100 



MR. E. C. BOUSFIELD THE 



The most beautiful of all the species of Dero ; but somewbat 

 anomalous iu tbe position of tbe first dorc^al bristles and in 

 tbe possession of palpi. Only found among the fibrous bundles 

 of tbe dead stems of C^perus (in tbe Royal Botanic Gardens), 

 which must be pulled apart to obtain the worms. 



JVofe. — Tbe 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. Ivii. p. 499. 



3. Blainville. — Planches, Zool. Vers et Zooph. pi. xxiii. 



4. Bosc— Vers, i. p. 203. 



5. Bousfield. — Report Brit. Assoc. Adv. Sci. 1885, p. 1097. 



6. D'Udekf-m.— Bull. Ac. Roy. Brux. 1885, p. 549, f. 1. 



7. Duces.— Ami. Sci. Nat. ser. 2, t. viii. p. 31, p]. 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 Groenlandica, p. 315, no. 269. 



11. Gervais.— Bull. Ac. Roy. Brux. 1838, p. 18. 



12. Grube. — Arch, fiir 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. MijLLER. — Zool. Danic. Prodr. no. 2651. 



17. M'uLLER. — Verm. Terr, et Fluv. &c. pt. ii. p. 22. 



18. MijLLER — VonWiirm. des siiss. u. salz. Wass. p. 90, pi. v. 



19. CEasTED.— Kroy. Nat. Tidssk. Bd. iv. 2, p. 133. 



20. Oken. — Lehrbuch der Naturg. iii. pt. 1, p. 363, pi. xi. f. 2. 



21. Pknnant.— British Zoology, 1812, iv. p. .98. 



22. Perrier. — Arch, de Zool. exp. et gen. i. p. 65, pi. i. 



23. Rees's Cyclopaedia. — Art. JVais. 



24. RosEL. — Insecten-BelustiguTig, lii. p. 581, pi. xciii. 



25. ScHMARUA. — Neue wirbellose Thiere, ii. 9. 



26. Semper.— Arb. Zool. Inst. Wiirzb. 1877-78, p. 106, pi. iv. f. 16. 



27. Shaw.— Naturahst's Miscellany, t. 452. 



28. Stewart. — Elements Brit. Zool. p. 391. 



29. Tauber. — Annulata Daniea, i. p. 75. 



30. TuRTON.- — British Fauna, p. 137. 



SI. Vejdovsky.— Syst. u. Morph. der Oligoch. pp. 27 & 117- 



DESCRIPTION OF THE PLATES. 

 Plate III. 



Fig. 1. Dero ohtum. The whole worm, enlarged from a photograph of the 

 living object. 



2. A dorsal view of the branchial area and processes of D. ohtusa, drawn 



from life, x 75. 



3. The same. A copy of D'Udekem's original figure. 



