DISTOMUM OIRTllGEEUM. 299 



d. c. Dorsa commissure, d. r. s. Duct of receptaculum seminis. e. c. 

 Excluded cells of embryo, eg. Egg. eg. c. Egg-cell. ep. c. So-called 

 epidermal ceils, ex. c. Excretory canal, ex. cl. Excretory cell from bladder. 

 ex. bl. Excretory bladder, e. i. c. Eggs in cyst cavity, e. i. u. Eggs in uterus. 

 /. Apparent fibrils in excretory cells. /. mt. Eormative material for cyst. 

 f.uL Fundament of uterus, jl. Elagellum of flame-cell. g.al. Genital atrium, 

 gl. Osmicated fat globules, gl. c. Gland-cells at exit-duct of bladder. /. cor. 

 Cortex which splits to form the ventral surface, i. cy. Irregular cuticle. /. 

 Lid of egg-shell. Z. d. Laurer's duct. /. m. Longitudinal muscle, m. c. 

 Developing muscle-fibres, m. c. s. Musijle-cells for cirrus-sac. m. d. Main 

 duct of excretory system, m. f. Muscle-fibres, m. h. Connective-tissue 

 surrounding muscles of the host. ??. ICucleus of reserve cell of bladder. 

 n. sy. Nervous system. 71. d. c. Nucle.is of disintegrating excretory cell. 

 nn. Nucleus of flame-cell. n.y. Nucleus o'i yolk-cell. 0. s. Oral sucker. 0. v. 

 Opening of vagina, oe. CEsophagus. ov. Ovary, ovid. Oviduct, p. Body 

 parenchyma, pk. Pharynx, p. 'pli. Pre-pharynx. pi. Protoplasmic layer 

 under cuticle, pr. gl. Prostate gland-cells, pr. t. Prostate tube. r. s. Re- 

 ceptaculum seminis. r. cor. Remainder of cortex, sh. gl. Shell-gland, sp. 

 Cuticle with spinelets. st.^ sL" st.^ Strata of cyst wall of adult and of 

 cuticle, t. Testis, t. h. Testis of host. ut. Uterus. ?>., Small vacuoles in 

 excretory cells. ».o The small vacuoles collected into larger vacuoles, v.^ 

 Great vacuoles full of granular contents. 1J.4 Emptied vacuoles, v.e. Vesicular 

 cell. V. s. Vesicula seminalis. vt. s. Ventral sucker, y. c. Yolk-cell. y. d. 

 Yolk-duct. yl. gl. Yolk-gland. 



EXPLANATION OF PLATES 24—26, 



Illustrating Mr. Ernest Warren's memoir on ^' Distomum 

 Cirrigerum, v. Baer." 



Fig. I. — X 20. The free animal from the side, viewed as an opaque 

 object. 



Fig. II. — X 88. The free animal from the ventral surface, viewed as a 

 transparent object. 



Fig. III. — X 33. The free animal from the side, viewed as a transparent 

 object. 



Fig. IV. — X 33. An encysted animal in the act of escaping from its cyst. 

 Eggs may be seen inside the cyst. 



Fig. V. — X 100. The female generative organs, semi-diagrammatic, con- 

 structed from serial sections and viewed from the side. Notice the close 

 connection of Laurer's duct with the receptaculum seminis. 



