Fig. 1^5. M. giganteum, n. sp. 



» l'. (Zeiss CC. Oc. 2. Cam.-luc. (_)smic acid, Hæmatoxylin.) Portion of a luirizontal section, taken troni llu' anterior 



margin of the bod)-, a., h. .Sul)-cctodcrmal testes, n. Nerve-brancli of the ist pair of fine nerves, n'. Branch 

 passing to the testis (a.), c. Cells, occurring alongside the nerves, tm. Trans-sected intestinal branches. 



» 2. (Zeiss F. Oc. i. Cam. -inc. Borax-carmine, Picric acid.) Portion ofatransver.se section, showing a dorsally situated 

 sub-ectodcrmal testis whose spermatozoa are, in one place (c), seen to pass through the ectoderm. At another 

 place (6.) the ectoderm is very thin. At 6. and, also, especially, at c, it may be seen that the ectoderm becomes 

 protuberant, a. Collection of undeveloped nuclei in the protoplasmic mass, rø., m'., m".. m^. Dermal muscles which 

 are separated by the multitude of spermatozoa. m". Similar muscles. d. Cavities in tlu- connective-tissue on the 

 outer side of an intestinal branch. 



s 1,. (Zeis F. Oc. I. Cam.-luc. J5orax-carniine, Picric acid.) Portion ol a transverse section, taken from the margin of 



the bod>-, showing a sub-ectodermal testis situated here, its spermatozoa are, in several places {a., b., c, d., f.'j, 

 about to pass through the ectoderm (ec). g. Collection of nuclei, h. Protoplasmic mass in which many nuclei 

 arc situated, but without any cellular margins being visibU'. i, /., /. Deeply staining corpuscles, or nuclei. I. Collection 

 of spermatozoa. Jc. Connective-tissue nuclei, n. Nerve, t.m. Intestinal branch. 



» 4. (Zeiss F. Oc. i. Cam.-luc. Osmic acid, Hæmatoxylin.) Portion of a transverse section taken from the anterior 

 part of the body, showing a large nucleus (a.), situated in the fibrillar mass in the side of a sub-ectodermal testis, 

 from which a prolongation (6.) issues, k. Nuclei resembling connective-tissue nuclei. m. Muscles, ec. Outline of 

 the ectoderm. 



» 5. M. giganteum. (Zeiss CC. Oc. 4. Cam.-luc. Borax-carmine, Picric acid.) Portion of a transverse section passing 



through a penis, a. Epithelium of the ductus ejaculatorius in which spermatozoa and undeveloped spermatoc)'tes 

 are seen. m'. Slender sphincters, m. m". Demial muscles, e. F,ctoderm. p. Spermatozoa, more magnified. 



s 6. M. graffi, n. sp. (Zeiss CC. Oc. i. Cam.-luc. Borax-carmine, Picric acid). Section of the exterior part of a 

 vesicula seminalis, showing the papilla (a.) with elongate cells, the prolongations penetrating into the subjacent 

 connective-tissue. b. More-developed epithelium situated opposite the papilla. Many undeveloped spermatocj'tes 

 are seen in the contents of the vesicula. p. Two of these spermatocytes, more magnified. 



» 7. M. giganteum, n. sp. (Zeiss F. Oc. i. Cam.-luc. Borax-carmine, Picric acid.) This fig. is similar to fig. 3; the 

 sub-ectodermal testis is. however, less developed. Only a few spermatozoa (s.) are present, d. Protoplasmic mass in 

 which nuclei (6.) are situated, a. Less-granulous nuclei with distinct nucleoli, m. Muscles, c. Large nuclei situated 

 under the ectoderm. 



/' 8. M. graffi, n. sp. (Zeiss hom. un. '/is- ^c. i. Cam.-luc. Osmic acid, Hæmatoxj-lin.j A. B. C. 3 portions ot 

 horizontal sections showing the structure of the testes, a.. a\ Large nuclei, (probably of spermatogones), b., c, d., e.,f. 

 Nuclei in difterent stages of division, g. Nuclei are seen, here, quite loosened out. h. Cells containing darkly-stain- 

 ing corpuscles. «"., h' . Spermatocytes. I. Nucleus (probably of cytophores). s., s. Heads of spermatozoa m process 

 of development. In C. the spermatozoa are seen arranged, radially, sp. Trans-sected spermatozoa. 



» 9 — 13. M. graffi, n. sp. (Zeiss F. Oc. i. Cam.-luc. Borax-carmine, Picric acid.) 



9. Section of the epithelium of the anterior part of the stomach, behind the oesophagus. 



:. 10. Section of the same, somewhat farther back, in the posterior part of the stomach. 



» II. Section ot the same sail farther back. rø. Muscles in the wall of the stomach. 



;; 12, 13. Two parts of section of the epithelium of an intestinal branch, showing the different lengths of the cells. The 

 cells, in fig. 13, are situated close to those of fig. 12. n. Trans-sected canals, k. Connective-tissue nuclei. 



» 14. M. giganteum, n. sp. (Zeiss F. Oc. i. Cam.-luc. Borax-carmine, Picric acid.) Section of the epithelium of the 

 anterior stomach. The cells are much elongated, and very slender, and have their nucleiplaced, at a varying height 

 some distance above the base. At the base, muscles are seen in the wall of the stomach. 



» 15. M. cirriferum, F. S. L. (Zeiss F. Oc. i. Cam.-luc.) Section of the epithelium of the dorsal side of an intestinal branch. 



» 16. M. cirriferum, F. S. L. (Zeiss F. Oc. i. Cam.-luc. Osmic acid. Borax-carmine.) Portion of a transverse section, 

 showing the epithelium ot the adjacent walls of two intestinal branches; the cells have a squareish form of varying 

 prominence; on the dextral side they are seen to diminish towards the ventral side of the branch, a. Connective 

 tissue wall. 



» I'J. 21. graffi, n. sp. (Arbitrarily magnified.) Portion of a section through the epithelium of the stomach, v. Trans- 

 sected canal. s.k. Canals in the connective-tissue, dissected longitudinall)-. Jc. Connective-tissue nuclei. a. Nuclei 

 of epithelial cells. 



» ig. M. cirriferum, F. S. L. (Zeiss F. Oc. i. Cam.-luc. Hæmatoxylin.) C)va, isolated by the brothers Hertwigs method 

 (osmic and acetic acids in seawater). In the nucleus of the largest cell corpuscles are seen, similar to those Beard 

 mentions as initial yoke-formation. The cells have a perfect globular form. 



>■ 19. M. giganteum, n. sp. (Zeiss CC. Oc. 2. Cam.-luc. Borax-carmine, Picric acid.) Portion of a transverse section, 

 showing a trans-sected segmental glandular sack. a. Cilandular tissue, covered by a cuticulum furnished with cilia. 

 sjili. Sphincters of the aperture, m. Fibrils of dorso-ventral muscles inserted in the walls of the aperture, m'. Radial 

 muscles, b. Elongate clavi-form cells occurring in the connective-tissue surrounding the aperture. In the aperture, 

 and in the inner cavit}', mucous gobules secreted from the glandular tissue are seen. tm. Trans-sected intestinal 

 branches. 



;. 20. M. cirriferum, F. S. L. (Seibert hom. im. '/g. Zeiss Oc. i. Cam.-luc. Borax-carmine, Picric acid.) Portion of a 

 transverse section, showing a trans-sected segmental glandular sack. spli. .Sphincters of the aperture, a. Glandular 

 tissue, furnished with a thick ciliated cuticulum. The cilia are longer than in M. giganteum (vide fig. 19). •;»., m'. 

 Dorso-ventral muscles, ov. Ova. 



;. 21. M. giganteum, n. sp. (Zeiss CC. Oc. 2. Cam.-luc.) Portion of a horizontal section, showing the oblong aperture 

 of a glandular sack, furnished with annular and radial muscles, m., m'. Dermal muscles. 



: 22. M. cirriferum-, F. S. L.. (Zeiss F. Oc. i. Cam.-luc.) Horizontal section of the circular aperture of a glandular 

 sack, furnished with annular and radial muscles. 



>. 23. M. graffi, n. sp. (Zeiss F. Oc. 1. Cam.-luc. Hæmatoxylin.) Section of one of the problematic organs (rudimen- 

 tary ovaries.') situated in branches of the uterus at the dorsal side of the stomach; the organ consists of closely 

 packed small cells with deeply staining nuclei, a. Tumefactions in the membranes of the cells (probabl)' membra- 

 nous nuclei), ov. Ova, situated in the same cavity as the problematic organ. 



» 24. 31. cirriferum, F. S L. (Zeiss F. Oc. 2. Cam.-luc. Hæmatoxj-lin.) Epithelial cells, from the intestinal branches, 

 isolated b\- the brothers Hertwig's method (osmic and acetic acids in seawater). a. Cell in which no nucleus is 

 seen, but only a granular substance, b. Cell whose protoplasm contains globules, c. Oblong cell. 



■■' 25. Taenia myzostomu, n. sp. (Zeiss CC. Oc. 4. Cam.-luc. Picro-carmine.) Taken from a horizontal section of M. 

 graffi. Three trans-sected suckers are seen, into which parts of ova have been sucked in. This cj'sticercus was found 

 in the body-cavity of the anterior body of the animal. In the intestinal branches, of the same specimen, a few 

 cysticerci were, also, found. 



>■ 26. M. cirriferum, F. S. L. (Zeiss F. Oc. i. Cam.-luc. Hæmatoxylin.) Muscles isolated by the brothers Hertwig's 

 method (osmic and acetic acids in seawater). In a, the nucleus is situated between the branchs of the one ex- 

 tremity. Protoplasm is situated between the branches of the other extremity. In c. and b. the nuclei are situated in 

 a protoplasmic thickening at the side of the fibre, which is, also, the case with the fourth muscle. The space between 

 the branches of one extremit\', is here, filled with protoplasm. 



