508 
PAUL PELSENEEB. 
Fig. 8. — Head of Pneumodermon. Dorsal aspect. 
Fig. 9. — Head of Pneumodermon. Lateral view. a. Labial tentacles. 
b. Nuchal tentacles, c. Acetabuliferous buccal appendages, d. Fins. e. Lips. 
f. Foot. g. Orifice of the penis. 
Fig. 10. — Head of Creseis. Dorsal aspect. (After Gegenbaur.) a. Mouth. 
b. Tentacles with eyes. c. Foot. d. Fins. e. Mantle. 
Figs. 11 — 22. — Clione. 
Fig. 11. Transverse section of a buccal cone. a. Annular muscular 
layer, d. Longitudinal muscular layer, b. Internal glandular cells. 
c. Epithelial covering. 
Fig. 12. Longitudinal section of a buccal cone. Letters as in Fig. 11. 
Fig. 13. An epithelial group of the section Fig. 11, more magnified. 
a. Annular muscular layer, b. Longitudinal muscular layer. V . Nu- 
cleus. c. Internal glandular cells, d. Their fibroid secretion, e. Re- 
ticulated connective tissue, f. Epithelial cells, g. Its button-like 
termination, h. Cellular contents, i. Sensorial cell. j. Its nucleus. 
k. Its rod-like prolongation. 1. The striated conic part of the rod. 
m. The terminal disc of the rod. n. Refracting body. 
Fig. 14. — An epithelial group, showing the reticulated aspect of the rod 
of the sensorial cell. a. Prolongation of the sensorial cell. b. Striated 
part of the rod. c. Refracting body. d. Epithelial cells, e. Fibroid 
secretion of the internal glandular cells. 
Fig. 15. — An epithelial cell, showing the striae of the membrane. 
a. Striae of the cellular membrane, b. Cellular contents, c. Fibroid 
secretion. 
Fig. 16. — Longitudinal section of a group of glandular cells of the in- 
terior of a buccal cone. a. Internal glandular cells, b. Its nucleus. 
c. Basement membrane, d. Prolongation of the glandular cell. 
Fig. 17. — Transversal section of several groups of internal glandular 
cells, a. Glandular cells, b. Nucleus, c. Basement membrane. 
Fig. 18. — A glandular cell adjacent to the muscular part of the cone, 
showing the passage of the cellular substance to the fibroid secretion. 
a. Nucleus, b. Cellular contents, c. Fibroid secretion. 
Fig. 19. — Transverse section of an epithelial group, passing a little 
above the annular muscular layer, a. Sensorial cell and its nucleus 
b. Reticulated connective tissue, c. Fibroid secretion of the internal 
glandular cells. 
Fig. 20. Ditto, through the base of the group, a. Prolongation of the 
sensorial cell. b. Reticulated connective tissue, c. Fibroid secretion 
of the internal glandular cells. 
Fig. 21. Ditto, through the extreme base of the epithelial cells, a. Pro- 
longation of the sensorial cell. b. Refracting body. c. Base of the 
central epithelial cells, d. Fibroid secretion, e. Connective tissue. 
