JOURNAL OF MICROSCOPICAL SCIENCE, 



DESCRIPTION OF PLATE III, 



Illustrating Mr. Moseley's paper ou Stylochus Pelagicus, 



a new Species of Pelagic Plauariaiij with Notes on 



other Pelagic Species, on the Larval Forms of Thysano- 



zoon, and of a Gymnosomatous Pteropod. 



Fig. 1.- — Larval planariau, Tbysauozoon ? Magnified 60 diameters. 

 Fig. 2.— Same in earlier stage. Magnified 50 diameters. 

 Fig. 3. — Cell-bearing cilia, from the body processes of the same seen in 

 Fig. 1. Actual diameter of the cell "02 mm. 



Fig. 4. — Portion of the epidermis of the same larva. Magnified 500 

 diameters, showing the arrangement of the pigmented cells, rod cells, &e. 



Fig. 5. — Cells containing oily spherules from the body mass of the same 

 larva. 



Fig. 6. — Rod cell of the same, with the rods packed so as to form a 

 hollow cylinder inside it. Magnified 800 diameters. 

 Fig. 7. — Single rod "OlS mm. in actual length. 

 Fig. S. — The same rod seen in optical transverse section. 

 Fig. 9. — Shjlochns Pelagicus. The entire animal viewed from the under 

 surface by transmitted light. Magnified 9 diameters. General view to 

 show the arrangement of the digestive nervous and reproductive systems, 

 and the relative positions of the generative and digestive orifices. Drawn 

 with the camera lucidse. 



Fig. 10. — Stylochus Pelagicus. Sketch to show the arrangement of the 

 eye spots around the cephalic ganglia. The spots are placed symmetrically 

 in two pairs of patches anterior aad posterior, and in two rings one 

 round the base of each tentacle. 



Fig. W.— Sti/lochus Pelagicus. Generative organs much enlarged, and 

 represented somewhat schematically. 

 . S. Sheath of j)harynx. Ph. Pharynx. O. Ovary. A. G. Albumini- 

 parous gland. U. Muscular wall of the uterus. F. G. Femalie 

 generative aperture. T. Testis. V. D. Vas deferens. V. S. Vesi- 

 cula seminalis. Pt. Prostate. S. P. Sheath of penis. C. P. 

 Caviiy of penis. M. G. Male generative aperture. R. M. Retractor 

 muscular fibres of the penis. 

 Fig. 12. — Pelagic planarian sp.? as viewed from below by transmitted 

 light. Magnified 18 diameters to show the relative positions of parts. 



G. ganglia. M. mouth. The ultimate ramifications of the digestive 

 canals are shown only at the fore and hinder part of the animal. 

 Fig. 13. — The ganglia of the same animal magnified with the ramifications 

 of the digestive system in immediate relation with them and the eye spots. 

 Magnified 72 diameters. 



Fig. 14. — Pteropod larva. View of the larva from the dorsal surface. 

 Magnified 250 diameters. 



R. Radula. R. M. Retractor muscles of buccal mass. CE. CEsopha- 

 gus. G. Supra-oesophageal ganglion. G'. Infra- oesophageal gang- 

 lion. O. Otolith. D. Digestive tract. A. Large transparent 

 cells surrounding the upper part of the digestive tract. 

 Fig. 15. — View of the anterior part of the same larva from the ventral 

 surface. 



L'. Extensile lip. B. Buccal mass and muscles. L. Foot. L". Ap- 

 pendage of foot. Zipfelformige Anhang of Gegenbaur. O. Oto- 

 liths. X. Anus. 

 Fig. 16. — Transverse section (optical) of the same larva in the region of 

 the upper part of the digestive tract. 



E. Epidermis. D. Digestive tract. A. Large cells. 



