Fig. I. M. gigaitteiim, n. sp. (Zeiss CC. Oc. 3. Cam.-luc. Horax-carmiiu-, Picric acid.j ?(irUon ot" a transverse section, 

 showin" a parapodial ganglion and its fibrillar stem which passes into the parapodiuin, and communicates with the 

 epithelium (a.) of the opening of the canal in which the chief hook is situated, n.c, n.c. Ganglionic cells, situated 

 under the ectoderm of the parapodium. b. Annular muscles surrounding the canal opening, ov. Ova. fm. Intestinal, 

 branchial epithelium. Ii.k. Portion of hook-gland. 



» 2. (Seibert, horn. im. '/a- '/-'-'i^i^ Oc. 1. Cam.-luc.) Portion of a section similar to fig. 1, showing the parapodial 

 extremit)- of the fibrillar stem («/.) issuing from a parapodial ganglion; more magnified. d. Opening of the canal 

 in which the chief hook is situated, c. Epithelium of the same aperture, m., m. Annular muscles surrounding the 

 aperture. The upper bundle ot muscles form a constriction in the fibrillar stem. h. Bundle, of fibrils, diverging 

 from the mam-stem (n.f.). a. Peculiar organ of glass bulb-receiver form, (possibl)-, analogous to X. in fig. 3). 

 nc. Ganglionic cell situated under the ectoderm, nc. Ganglionic cells situated alongside the fibrillar stem. 



» 3. M. graffi, n. up. (Zeiss CC. Oc. 4. Cam.-luc. Borax-carmine, Picric acid.) Portion of a transverse section, show- 

 ing a parapodial ganglion with its giant-cells {nc). h. Nucleus of a cell. d. Fibrillar prolongation of cell passing 

 along the outer side of the ganglion., nc. Cell with 2 distinct prolongations. Most of the cellular prolongations 

 Converge in the middle of the ganglion, and are directed towards the parapodium, forming intricate traversations (c.) 

 at the peculiar organ (X.) of glass bulb receiver form v\ith its neck (xu.) passing into the parapodium. ne'. Small 

 ganglionic cells. Similar cells are situated in the lower part of the parapodium. a. Nucleolus pertaining to a 

 destroyed (.?) nucleus; whose contents are seen distributed in the upper end of the cell. m. Muscles adhering to the 

 manubrium of the supporting rod (s. h.). 



» 4. 31. graffi, n. sp. (Zeiss CC. Oc. 5. Cam.-luc. Borax-carmine, Picric acid.) Portion of a horizontal section through 

 a parapodial ganglion, h. Nucleus of the ganglionic cell. c. Prolongation ot the ganglionic cell [nc.) seen, surrounded 

 by numerous connective-tissue nuclei [k'.) as usually is the case. 1;. Connective-tissue nuclei, p. Problematic organ 

 situated in the centre of the ganglion, above the organ X. illustrated in fig. 3. r.h. Trans-sected hooks, h.k. Gland- 

 ular mass of the hook-apparatus, a. Large cell in the glandular mass. 



» 5. M. graffi, n. sp. (Zeiss CC. Oc. 2. Cam.-luc. Borax-carmine, Picric acid.) Portion of a horizontal section, showing 



the nerves («'., n-., n^., n*.) running to a parapodial ganglion, n-"., n'^. Nerves running to the cirri, h., r.h. Support- 

 ing rod, chief hook and reserve hook. h.k. Glandular mass. 



» 6. M. graffi, n. sp. (Zeiss F. Oc. i. Cam.-luc. Borax-carmine, Picric acid.) Horizontal section through the lower 

 part of a parapodial ganglion, in which the bulbs (X) of the two receiver-shaped organs (illustrated in fig. 3, X) 

 are trans-sected. a. Spongious mass at the side of the dextral receiver-bulb. h. Vacuolous part of the sinistral 

 bu b, the contents of which appear to be coagulated. d. Ganglionic cell. N. N. Nerves (similar to n^. and w*. in 

 fig. 5) running to the ganglia, and ramifying into branches [n., n'"., n\, n-., n'^). s.h. Chief hook. hk. Glandular mass 

 of the hook-apparatus, c. Outer la_\-er of the glandular mass, containing larger cells, m. Muscles. 



» 7. M. graffi, «. sp. (Zeiss CC. Oc. 3. Cam.-luc. Osmic acid, Hæmatoxylin.) Portion of horizontal section through 

 the lower part of a parapodial ganglion, x., x. Transsected bulbs of the receiver-shaped organs. /*., sh., rh., rh'. 

 Hooks, e. Ectoderm of the parapodium. m., in'. Muscles. 



» 8. M. graffi, it. sp. "(Zeiss CC. Oc. 4. Cam.-luc. Borax carmine. Picric acid.) Horizontal section, passing, t;ansver- 

 sally, through the extremit}' of a parapodium. xu. The trans-sected prolongations of the 2 receiver-shaped organs. 

 Their contents are seen shrunk together, n.. n. The 2 trans-sected fibrillar stems of the parapodial ganglion, a, 

 Channel in the glandular mass {hk.) of the hook apparatus. /(. Chief hook. s./f. Supporting rod. m. Annular muscles. 



» 9. M. gigantemn, n. sp. (Zeiss F. Oc. 2. Cam.-luc. I5orax-carmine. Picric acid.) Portion of a transverse section 



showing groups of ganglionic cells (.?) (nc. nc A situated under the epithelium of a parapodium. The cellular margins 

 were not exactly distinguished. 



» 10. M. graffi, n. sp. (Zeiss F. Oc. i. Cam.-luc. Hæmatoxylin.) Portion of a horizontal section through the lower 

 part of a parapodial ganglion, showing small ganglionic cells {nc.) to be situated here, a., a. Parts of the giant-cells. 

 k. Connective-tissue nuclei, sh. Chief hook. 

 » II. M. graffi, n. sp. (Seibert horn. im. 7,6. Zeiss Oc. i. Cam.-luc. Bengal rose.) Isolated giant-cell ot a parapodial 

 ganglion (from a transverse section). Adhering to it, the Inilb (x.) of one of the receiver shaped organs is seen. 

 xu. Prolongation of this organ. c. h. Point where the fibrils of the cell pass into the prolongations and traverse 

 each other, a., I. Small cells, situated at the lower extremit\- of the giant-cell. k. Connective-tissue nuclei. 

 » 12. M. graffi, n. sp. (Seibert hom. im. '/,,;. Zeiss Oc. i. Cam.-luc. Borax-carmine, Picric acid.) Section ot the bulb 

 of the receiver-shaped organ, showing its communication with fibrils from the ganglion, and the concentric structure 

 of the outer laver of its contents. 



