THE TREMATODA 



Europe (Fig. IV.). Diclidophora, Goto (non Diesing), (Fig. II. 4) ; 

 Dactylocotyle, v. Ben. and H. ; Cyclobothrium, Cerf. ; C. sessilis, Goto, oral 



Fia. I. Anatomy of a Schematic Heterocotylean. 



1. Dorsal view, showing the alimentary and nervous systems, o, mouth, on the ventral 

 surface, the outline being therefore clotted ; b, pharynx ; c, bifurcate intestine ; rf, branching, 

 intestinal caeca ; e, post-genital union of the two intestinal limbs ; e', median portion of the 

 intestine, which is continued backwards, and gives origin to caeca in the posterior sucker (or 

 cotylophnre, as the case may be) ; /, excretory pore, right and left, situated just dorsal to the 

 margin of the body ; g, the vaginal pore ; it is here represented as paired ; but frequently it is 

 unpaired ; h, anterior nerve, right and left, arising from the brain ; j, tho cerebral ganglion, 

 which carries on each side a couple of eyes, represented by white spots ; k, marginal or lateral 

 nerve ; I, dorsal nerve, which is frequently present ; m, ventral nerve. The nervous system 

 is shown in greater detail in Fig. XXI. ; n, the right anterior sucker ; it is unconnected with 

 the oral cavity, and is termed " lateral " ; o, posterior sucker ; p, a booklet projecting from the 

 posterior sucker; r, the genito-iutestinal (Laurer's) canal, entering the right limb of the in- 

 testine. 



2. Plan of the excretory system, seen from the ventral surface, a, mouth ; 6, genital 

 pore and atrium, here represented as median, but it may lie on the left of the median line ; /, 

 excretory pore ; g, contractile excretory bladder, right and left ; h, large excretory duct, 

 passing backwards to the hinder end of the body ; fc, the forwardly-directed (ascending) canal, 

 in continuity with the duct posteriorly, and running to the anterior end of the body, giving 

 off irregularly arranged branches, which subdivide to form capillaries ; i, capillaries terminating 

 in flame cells, which are indicated by the terminal thickenings ; j, transverse anastomotie 

 vessel, which is frequently present behind the genital organs ; , the left anterior "lateral" 

 e posterior sucker, which is here, as so frequently, subdivided into compartments 



a lateral loculus ; g 7 , the central loculua 



sucker ; o, the posterior suc 



or "loculi" by radiating ridges; p, a hooklet ; </, 



which may, or may not, be present. 



3. Plan of the genital organs, seen from the ventral surface ; b, genital atrium ; c, uterus ; d, 

 gennarium ; e, portion of the right limb of the intestine into which the genito-intestinal canal 

 opens ; /, longitudinal vitellarian duct, from each of which a transverse duct passes inwards to 

 enter the germ duct ; g, vitellarium ; h, testis, consisting of a number of follicles ; i, the sperm 

 duct ; j, ootype, surrounded by " shell glands " ; between it and the gennarium is the germ duct ; 

 fc, vagina, right and left, connected internally with the median vitello-duct ; I, vaginal pore ; 

 m, the sperm duct ; n, o, p, as before ; r, genito-intestinal (Laurer's) canal, passing from the 

 oviduct to the intestine ; s, excretory pore ; t, penis. 



cavity of Chaerops japonicus. Heterobothrium, Cerf. ; Vallisia, Per. Par. ; 

 V. striata, Per. Par., on gills of Lichia. Anthocotyle, v. Ben. and H. 



