PARASITIC WORMS BERMUDA. I. TREMATODES. 223 



Synechorchis megas, n. g. et n. sp. 

 (PI. Ill, Figs. 13-22). 



1. Morphology. 



General Appearance. — Twenty-four specimens of this trematode 

 were studied, twelve of which were fixed in 2% formol and twelve in 

 vom Rath's osmio-sublimate mixture. In general the body is boat- or 

 cradle-shaped, the dorsal surface being strongly convex both longi- 

 tudinally and transversely and the ventral surface correspondingly 

 strongly concave. The body tapers slightly toward the anterior end 

 making the posterior end the broader and more bluntly rounded. In 

 unmounted specimens the length varies from 4.2 mm. to 9 mm. and 

 the width from 2.2 mm. to 3.2 mm. The thickness of the body is 



1.04 mm. with slight variations. No cuticular spines or scales were 

 found. 



At the anterior end of the body is a well defined terminal cephalic 

 hood or collar (PI. Ill, Figs. 18, 19), 1.50 mm. to 1.65 mm. wide and 



1.05 mm. to 1.17 mm. long. The dorsal margin of the hood is unbroken 

 but the ventral margin is indented by a wide shallow notch or hilus 

 (Fig. 17). The whole hood has the general appearance of a cocked 

 hat; its ventral face is slightly concave, with the lappets not promi- 

 nent, giving the whole somewhat the shape of a kidney. A well 

 defined muscular oral sucker lies in the ventral cupped face of the hood, 

 but an acetabulum is not present (Figs. 17, 18, 22). 



At the posterior end of the body, on the dorsal surface, in the 

 median line is a funnel-shaped opening, which marks the termination 

 of the excretory system. The male and female genital pores are 

 separate and salient; they lie on the medial side of the left intestinal 

 caecum (Figs. 17, 22) at the level of the posterior margin of the 

 anterior fourth of the body. The large cirrus was extruded in several 

 of the specimens examined (Fig. 17). 



Digestive System. — The oral sucker, having a fairly well developed 

 musculature, opens directly into the oesophagus. It measured 0.66 

 mm. wide by 0.60 mm. long. A pharynx is not present. The length 

 of the oesophagus varies much; in some specimens it appears to be 

 wanting, in others it may reach a length of 0.50 mm. The wide 

 intestinal caeca occupy a lateral and dorsal position in the body and 

 extend from the oral sucker in an undulating course to near the end 

 of the body, where they end blindly. The caeca throughout their 



