PAKASITIC WORMS BERMUDA. I. TREMATODES. 217 



or secondary ridges. An oesophagus is not present, the common 

 transverse caecum following immediately behind the pharynx. On 

 each side of the pharynx a single well defined diverticulum extends 

 cephalad from the transverse caecum lateral, or dorso-lateral, to the 

 oral sucker to a height of one half the sucker's depth. These diver- 

 ticula may or may not bifurcate at their terminations. The lateral 

 caeca are broad and deep and they extend in an undulating course to 

 the posterior end of the body, where they end blindly, giving off in 

 their course numerous small lateral and deep ventral diverticula. 

 The caeca are deeper than wide and lie in a plane mid-way between 

 the dorsal and ventral surfaces in the lateral fields of the body (PI. II, 

 Fig. 12). 



Male genitals. — The two testes (PI. I, Figs. 1, 5), of medium and 

 nearly equal size, irregular in shape and with undulating to slightly 

 lobed margins, are situated in the same transverse plane midway 

 between the anterior and posterior ends of the body. The testes vary 

 in size from O.oS mm. to 0.68 mm. by 0.34 mm. to 0.54 mm. The 

 right one is slightly behind the posterior margin of the acetabulum 

 and its left end projects beyond the median plane into the left half of 

 the body. The bulk of the left testis is farther from the median plane 

 than is the left margin of the acetalnilum, and its anterior end extends 

 a little farther forward than the posterior margin of the acetabulum. 

 From the antero-dorsal margin of each testis a small vas efferens 

 passes obliquely forward and toward the median plane. These unite 

 just cephalad and dorsad to the OA'ary to constitute the vas deferens 

 (PI. I, Fig. 3); this continues in the median area to the base of the 

 cirrus pouch, which it enters. The cirrus pouch, though compara- 

 tively short, is an elongated pear shaped organ situated immediately 

 anterior to the acetabulum, with its long axis nearly perpendicular to 

 the frontal plane of the body. It is 0.96 mm. long and from 0.24 mm. 

 to 0.2S mm. in diameter, I)eing a little longer than the acetabulum is 

 deep, so that its base lies slightly dorsad and cephalad to the acetab- 

 ulum. It is so short that it does not bend around the acetabulum. 

 The vas deferens upon entering the base of the cirrus pouch vmites 

 with the enlarged transversely coiled seminal vesicle, which fills the 

 basal third of the pouch. The seminal vesicle connects, in turn, with 

 a comparatively wide prostatic duct, which has an undulating course 

 and tapers toward the distal end of the pouch, where it merges into 

 the ejaculatory duct of the short cirrus. 



The cells forming the prostate gland (PI. I, Fig. 3) occupy the 

 peripheral portion of the pouch and extend from the seminal vesicle 



