398 PROCEEDINGS OF THE ACADEMY OF [May, 



Clapar^de, E. Recherches Anatomiques sur les Oligochetes. Id., XVI (1862), 



pp. 217-291, Pis. I-IV, 

 DiTLEVSEN, A. Studien an Oligochaten. Zeit. f. Wiss. Zool., LXXVII (1904), 



pp. 398-480, Pis. XVI-XVIII. 

 Ferrionniere, G. Contribution k I'etude de la faune de la Loire-Inferieure. 

 Ann^lides oligochetes. Bull. Soc. Set. nat. Quest, IX (1899), pp. 242-4, 

 246-9, 294, PI. XIX. 

 Goodrich, E. S. On the Structure of Vermicidus Ii7nosus. Quar. Jour. Micr. 



ScL, XXXVII (1895), 253-267, Pis. XXVI-XXVIII. 

 Leidy, J. Marine Invertebrate Fauna of Rhode Island and New Jersey. Jour. 



Acad. Nat. Sci. Phila., Ill (1855), p. 148, PI. XI, fig. 64. 

 MiCHAELSEN, W. Oligochseta, Berlin, 1900. 

 Minor, W. C. Natural and Artificial Section in Some Chsetopod Annelids- 



Aynerican Journal of Science and Arts, XXXV (1863), p. 36. 

 Smith, F. Notes on Species of North American Oligochseta. Bull. III. State 



Lab. Nat. Hist., IV (1895), pp. 289-292. 

 Vaillant, L. Histoire des Annel^s. Paris, 1890, III, 2, pp. 421, 422. 

 Verrill, a. E. Report upon the Invertebrate Animals of Vineyard Sound and 



Adjacent Waters. Rep. U. S. Fish Comm., 1873, pp. 622-624, 324. 

 Verrill, A. E. New England Annelida. Trans. Conn. Acad., IV (1881), PI. 

 VIII, fig. 3. 



Explanation of Plates XXXII and XXXIII. 



Plate XXXII. — Monopylephorus glaber, figs. 1 to 6. 



Fig. 1. — Male genital duct entire, dissected. X 180. The histology is 



semi-diagrammatic. 

 Fig. 2. — Outline of a living nephridium in situ, seen from below. X 180. 



V, ventral blood vessel. 

 Fig. 3. — Outline of brain, from above. X ISO. 

 Fig. 4. — A ventral seta from VIII. X 335. 

 Fig. 5. — Three ccelomic corpuscles of different sizes. X280. 

 Fig. 6. — A pair of spermathecEe. X 55. 



Tubifex irroratus, figs. 7 to 11. 



Fig. 7. — Side view of entire male genital duct, the penis sac partly concealed 



behind the sperm reservoir; from a dissection and sections. X 180. 

 Fig. 8. — Two spermathecie from different worms; a, much and b, little 



distended with sperm. X55. 

 Fig. 9. — Ventral setse, a, from somite IV; b, from somite XL, and c, from 



the posterior end. X 335. 

 Fig. 10. — Ccelomic corpuscles, a, of the ordinary form; b, the homogeneous, 



colorless form. X 280. 

 Fig. 11. — Terminal portion of a dorsal capillary seta. X560. 



Tubifex hamatus, figs. 12 to 18. 



Fig. 12. — Outline of brain, from above. X 180, 

 Fig. 13. — A posterior dorsal seta. X 280. 



Fig. 14. — A dorsal seta from VIII, and a, tip of a ventral seta from the same. 

 \ X280. 



Fig. 15. — Two of the hooked dorsal setse from the middle region. X 280. 

 Fig. 16. — Outline of the male genital duct, with a portion only of the vas 



deferens represented. X 180. Funnel diagrammatic. 

 Fig. 17. — A copulatory seta retracted within its sac. X 280. 

 Fig. 18. — Outline of a nearly empty spermatheca. The line a-a shows the 



form of the same partly distended. X ISO. 



Plate XXXIII. — Lininodrilus subsalsus, figs. 19 to 22. 



Figs. 19 and 20. — Ventral and dorsal setse, respectively, from somite VI. 



X280. 

 Fig. 21. — Side \aew of the entire male genital duct, combined from several 



dissections. X about 100. 

 Fig. 22. — A spermatheca shown in outline. X about 100. 



