444 TREMATOBES OF THE NORTHUMBEIRLAND COAST 



Besides the above-mentioned characters it differs from Echino- 

 stomuin and StephanocKasmus in its very much thicker build 

 and blunt head spines. 



The genus Echinostephilla may be thus briefly described : — 



EcHiNOSTEPHiLLA n.g. Medium-sizcd worm with long 

 and narrow body, broadly rounded anteriorly and pointed 

 posteriorly, flattened dorso-ventrally. Suckers approximated, 

 strongly developed. Oral very small, and ventral large. 

 Body armed with a thick cuticle, covered with spines except 

 at the posterior end. Head armed with two complete rows of 

 numerous flat blunt spines arranged one directly in front of 

 the other. Prepharynx, pharynx, and fairly long oesophagus. 

 Intestinal lobes reaching nearly to the posterior end of the 

 body. Excretory vesicle long and narrow, vessels very much 

 branched anteriorly. Genital pore median, between ventral 

 sucker and fork of intestine. Testes oval, one behind the 

 other and close together, in posterior third of body. Cirrus 

 sac long and narrow, reaching some way behind the ventral 

 sucker, containing simple vesicula seminalis and long cirrus, 

 the latter armed internally with spines and protrusible for the 

 greater part of its length. Ovary in front of testes, uterus 

 long and winding, containing numerous eggs, the most ad- 

 vanced being in the miracidium stage with eye-spot. Vagina 

 long, winding, and muscular. Receptaculum seminis (?), 

 Laurer's canal (?). Vitellaria weakly developed, reaching from 

 posterior testis to near middle of vesicula seminalis. Type, 

 Echinostephilla virgida. 



