PARASITIC WORMS BERMUDA. I. TREMATODES. 219 



A diffuse, but well defined, shell-gland (PI. I, Fig. 6), or gland of 

 Mehlis, lies dorsal, and for the most part anterior, to the ovary. Its 

 posterior portion covers the anterior third of the ovary. The oviduct 

 penetrates the mass of shell-gland cells, which are connected with the 

 oviduct by numerous minute ducts. 



A globular compact receptaculum seminis (PI. I, Figs. 1, 5, 6), one- 

 third the bulk of the ovary, lies dorsal to the shell-gland and the 

 anterior half of the ovary. A small duct leaves its anterior margin 

 and turning mediad joins the oviduct soon after it leaves the ovary. 



At the junction of the receptaculum duct with the oviduct a tubular 

 Laurer's canal (Fig. 6) originates and in a slightly undulating course 

 makes its way dorsad and opens on the dorsal surface of the body 

 dorsal to the ovary and the posterior part of the acetabulum and 

 slightly to the right of the median line. 



The vitellarium (PI. I, Figs. 1, 2, 5) is rather striking in appearance 

 and is composed of two masses of convoluted tubules grouped in moss- 

 like patches, which lie in the lateral and latero-dorsal fields in the 

 middle three-fifths of the body. The patches are fairly definite and 

 constant in number, three patches being present on the right and four 

 on the left side. They extend forward of the anterior margin of the 

 acetabulum a distance approximately half of the diameter of that 

 organ, the posterior limit being about mid-way between the testes and 

 the posterior end of the body. The latero-dorsal patches are dorsal 

 to the testes and uterine coils. A fine vitelline duct (PI. I, Fig. 6) 

 connects with each other the patches or groups of each side and a 

 larger vitelline duct leaves the central group of each side and passes 

 transversely mediad to unite with the one from the opposite side to 

 form a small, but distinct, vitelline reservoir, which lies dorsal to the 

 left margin of the ovary. From the reservoir a small duct leads 

 cephalad and joins the oviduct a short distance beyond the union of 

 the receptaculum duct with the oviduct. 



The eggs (PI. I, Fig. 4) are numerous, spindle shaped, light brown in 

 color, with thick shell. A comparatively large, well-defined and easily 

 separated operculum is present, and a slight opercular rim can be 

 detected. The opercular pole is the more pointed. The eggs measure 

 0.0375 mm. to 0.0450 mm. in length by 0.015 mm. to 0.020 mm. in 

 width. The older eggs contain a well developed embryo, but many 

 appear empty, which probably indicates a non-fertile condition. 



Excretory System. — The excretory system (PI. II, Fig. 7) is volumi- 

 nous and consists of an enormous median dorsal reservoir, with a pair 

 of anterior prolongations. The reservoir is one-fourth the width and 



