NO. 6 gilbert: three new tret.iatodes 95 



slightly lobed, on median line anterior to testes; shell gland complex 

 well developed, just posterior to ovary; seminal receptacle absent; 

 Laurer's canal present; vitellaria of fifteen to seventeen large follicles 

 on each side, extending lateral to ceca from level of testes to posterior 

 level of cirrus sac. Uterus in transverse coils overlapping ceca from 

 ovary to female pore; eggs 18 to 22 by 8 to 13 ju,, thick shells, with 

 single filament at each pole. 



The genus name is for the host. The species name is from nav'icu- 

 la (small boat), which describes the boat-shaped body in contracted 

 specimens. 



Comparisons. This genus combines characteristics of several 

 other genera in the subfamily. The magnitude of the prostate, the 

 constriction present in this organ, and the relatively small cirrus and 

 large cirrus sac appear to be new characteristics. The excretory sys- 

 tem is apparently like that of Epibathra Looss, 1901 but most of 

 the other characteristics seem more related to Cricocephalus Looss, 

 1899; Adenogaster Looss, 1901; and Pleurogonius Looss, 1901. 

 Cricocephalus, however, has definite branches on the ceca, posterior 

 terminal glands on the body, a simple excretory system, no ventral 

 depression, and a much smaller prostate gland. Adenogaster has a 

 large prostate gland but it fills only half of the cirrus sac; the cirrus 

 is long, and the seminal vesicle lies coiled in a small area near the 

 prostate and does not continue posteriorly. Furthermore, numerous 

 glands cover the ventral surface of the body in Adenogaster but are 

 lacking in Iguanacola. Pleurogonius differs from Iguanacola in that 

 the limbs of the excretory vesicle do not have side branches and 

 unite anteriorly, the cirrus is simple, and the seminal vesicle not so 

 long. 



Myosaccus amblyrhynchi, new genus, new species 

 (Plate 11, figs. 5-8) 



Host: Amhlyrhynchus cristatus 

 Location: Intestine 

 Locality: Albemarle Island 



The following description is based on a study of five mounted, 

 and one sectioned specimen. 



The smooth, equally broad, weakly muscular body measures 4.66 

 by 1.77 mm. There are two papillae at the posterior end. The weak 

 muscular collar near the anterior end of the body is complete both 



