THE STRUCTUKb; AND AFFINITIES OF SACCOCIKEUS. 42^ 



5. Goodrich, E. S.— " On the Nephridia of the Polycliseta," Part 3, ' Quart. 

 Journ. Micr. Sci.,' vol. 43, 1900. 



e. Hatschek, B. — "Studieu iiber Entwickl. der Anneliden," 'Arb. Zool. 

 Inst., Wien,' vol. i, 187S. 



7. Hatschek, B. — "Protodrilus Leuckartii," ibid., vol. iii, 1881. 



8. Langerhans, p. — " Die Win mfauiia von Madeira," ' Zeit. f. wiss. Zool.,' 



vol. xxxiv, 1880. 



0. McIntosh, — . — "Note on Linotrypane apogon," 'Ann. and Mag. 

 Nat. Hist.,' ser. 4, vol. xvi, 1875. 



10. Marion, A. P., and Bobretzky.— " Anuelides du Golfe de Marseille," 



♦Ann. Sci. Nat. Zool.,' her. 6, vol. ii, 1875. 



11. Perrier, E. — " Sur un nouveau type . . . Polygordius Schneideri," 



' Comptes reudus,' vol. xc, Paris, 1875. 



12. Uljanin, B. — "Observations on Polygordius, etc.," iu Russian. 'Bull. 



des Naturalistes de .Moscou,' vol. i, 1877. 



EXPLANATION OF PLATES 27—29, 



Illustrating Mr. Edwin S. Goodrich's paper " On the Struc- 

 ture and Affinities of Saccocirrus." 



All the figures, excepting No. 7, are of Saccocirrus papillocercus. 



Fig. 1. — Nearly median sagittal section of tlie anterior end, showing the 

 root of the tentacle and the pharyngeal sac. Cam. D, oc. 2. 



Pig. 2. — Somewhat diagrammatic representation of the anterior end, drawn 

 from living specimens and preparations. Tue internal organs are seen by 

 transparency; the nervous system is coloured yellow. 



Pig. 3. — View of a portion of a genital segment of a female. The nepliri- 

 dium and sperniatheca are shown iu optical section. From the living. Oil 

 im. yV- 



Fig. 4. — Highly magnified view of a small portion of the wall of the sper- 

 matheca in optical section. 



Fig. 5. — Similar view of a portion of the wall of the intestine. 



Fig. 6. — Highly magnified view of a small region of the ventral surface of 

 a genital segment of a female, showing beneath the transparent skin the 

 'unction of the spermathecal and nephridial ducts. Oil im. ■^. 



