JOURNAL OF MICROSCOPICAL SCIENCE. 



DESCRIPTION OF PLATE XX, 



Illustrating a Paper on the " Structure of Various Land 

 Planarians/' By H. N. Moseley, M.A., F.R.S., 

 Fellow of Exeter College, Oxford. 



Fig. 1. — Anterior extremity of Geoplana Tmversii viewed from the side to 

 sliow the arrangement of tlie eye-spots. 

 a. Elongate patch of several rows of eye-spots, b. Single row of 

 eye-spots on the anterior tip of the body. Enlarged. 

 Fig. 2. — Three of the eye-spots of the same more highly magnified to show 



the oval spaces clear of pigment in which they lie. 

 Fig. 3. — Diagrammatic representation of the arrangement of the viscera 

 in the same as viewed from the dorsal aspect. The inteeu- 

 ment and muscles are supposed to be removed from the dorsal 

 surface so as to expose the viscera in siitl. The sheath or sac 

 of the pharynx and that of the generative organs are laid 

 open. The diverticula of the digestive tract are traced for a 

 short distance on the left side of the body only. 

 m. Circle showing the position of the mouth or aperture of exit of 

 the pharynx, ph. Pharynx lying within its sac or sheath, i i. In- 

 testine, a single mesially placed tube in the anterior region of the 

 body, but double in the hinder part, forking at the root of the 

 pharynx, the two tubes thus formed passing one on either side 

 of the sheath of the pharynx and generative organs, s. Septum, 

 separating the two intestinal canals in the hinder extremity of the body. 

 0. Ovary, od. Oviduct, u. Uterus, t. Testis, v d. Vas deferens. 

 vs. Vesicula seminalis. ej. Ejaculatory duct, b p. Bulb of the 

 penis. X. Accessory bulb, a. Cavity of the common sac containing 

 the generative organs. The special coverings of the various genera- 

 tive organs are dissected away, g o. Position of the generative outlet. 

 Fig. 4. — Generative organs of the same with their special coverings intact. 

 a. Sac containing the uterus, b. That containing the accessory 

 bulb. c. That containing the bulb of the penis and part of the 

 ejaculatory duct. d. That containing the vesicula seminalis and upper 

 part of the duct. 

 Fig. 5. — The generative organs of the same, seen from the side removed 

 from their sheaths and coverings. 

 V d. Vas deferens, v s. Vesicula seminalis. eJ. Ejaculatory duct. 

 b p. Bulb of the penis, a.-. Accessory bulb. p. Penis, y a. genera- 

 tive aperture, u. Uterus, od. Oviduct. 

 Fig. 6. — View of the lateral wall of the main digestive canal of the same, 

 showing the manner in which the diverticula open into the 

 canal. 

 Fig. 7. — Egg capsule of the same, cut open to show four fully formed em- 

 bryos within. In two of these the projecting pharynx is seen 

 and one embryo has been removed from the capsule. 



