566 



A DESCRIPTION OF THE ENTOZOA COLLECTED BY DR WILLEY 



EXPLANATION OF FIGURES ON PLATES LIV., LV. AND LVI. 

 PiEFERENCE LETTERS. 



.4. = glandular organ on male ducts. 



a.c. = alimentary canal. 



£.= dome-shaped organ on male duct. 



C.= glandular organ on vagina. 



c.s.^. = cavitj' of shell-gland complex. 



e.g. = cephahc ganglion. 



d.v. = dorsal excretory ves.sel. 



e.c. = water- vascular system. 



e.ca. =egg cavity. 



g.d. = genital ducts. 



Z.ra.= longitudinal muscles. 



VI, = muscular layer. 



M. = longitudinal nerves. 



0. = oesophagus. 



o.TO. = obUque muscles. 



ov. = ovary. 



p. = parenchymatous cells. 

 Pr. glds. = prostatic glands. 

 »S'. = sucker. 



s.g. = shell-gland complex. 

 t. = testis. 



t. r. = transverse excretory vessel. 

 ut. = uterus. 



». = vesicle of water-vascxilar system. 

 va. = vagina. 

 v.g. = vaginal glands. 

 v.d.=va,s deferens. 

 v.v. — ventral excretory vessel. 

 W.v. = water- vascular system in head. 

 y.g. = yolk-glands. 



PLATE LIV. 



Figs. 1 — 7 inclusive refer to Monostomiim trigorwceplicdum Rud. 



Fig. 1. Four sketches showing different aspects of Monostomum trigonocephalum Rud. 

 1 a. life-size. 1 6. x 8. 1 c. and \ d. x 10. 



Fig. 2. Section showing longitudinal and obliquely transverse muscle-fibres. On both sides 

 of the figure the parenchymatous cells are beginning to appear. 



Fig. 3. Longitudinal vertical section tlirough the body slightly to the left of the middle 

 line. 



Fig. i. Section through the glandular structure A, showing the communication of its 

 lumen with that of the dome-shaped structure B by means of a small muscular valve. 

 Anteriorly tlie vas deferens is seen cut in many places as it twists and curls in its muscular 

 sheath. 



Fig. .5. A longitudinal horizontal section, showing the loops of the uterus, and parts of 

 the alimentary canal, the water-vascular system, the testis, shell-gland complex, glandular 

 organ A, vas deferens and egg-cavity. 



Fig. 6. Shell-gland complex. The uterus is shown leaving this organ on the left, and 

 a coil of it lies to the right. Each contains ova witli deeply stained yolk granules. 



Fig. 7. Highly magnified section to show the structure of the peculiar organ C and its 

 relation to the vagina. The water-vascular canals with their lobes, a piece of the uterus 

 with the stalked eggs, part of the egg-cavity and some of the vaginal glands are also shown. 



Fig. 8. Head of Bothriocephalus plicatus Rud. x about 10. Dorsal or ventral view. 



Fig. 9. The same, lateral view. 



