b PEOCEEDIXGS OF THE NATIONAL MUSEUM, vol.63, 



ets, turns posteriorly and then dorsally behind the pockets, widen- 

 ing out into a rather elongate and not sharply defined esophageal 

 bulb from the right and left sides of which the broad intestinal ceca 

 emerge. Entire esophagus thick-walled and well supplied with 

 muscles. Intestinal ceca, considerably greater in dorso-ventral diam- 

 eter than in transverse diameter, reach almost to posterior sucker. 

 Ovary small, median, slightly elongate, in posterior part of body, 

 about at level of ends of intestinal ceca, on dorsal side; size about 

 0.26 by 0,195 mm. Ootj^pe and shell gland, immediately followed by 

 an enlargement of the tube which probably serves as a seminal 

 receptacle, situated immediately behind ovary on dorsal side. Uterus 

 coils transversely back and forth across body as it passes forward 

 to genital opening, finally uniting with sperm duct immedi- 

 ately in front of cirrus pouch, and opening on the genital 

 papilla by a short hermaphroditic duct. Laurer's canal passes 

 a short distance anteriorly on dorsal side of uterus, opening 

 on the middorsal surface about at the level of the middle of the 

 ovarj^ Vitelline glands in form of about 18 spherical follicles on 

 each side, quite distinct from one another, extending, along a curved 

 line on either side from the level of the posterior testis on the ven- 

 tral side, caudad, dorsad, and mediad, around the posterior ends of 

 the intestinal ceca. A transverse vitelline duct stretches across the 

 space between the two series of follicles, a common duct passing from 

 this to the ootype. Testes two, somewhat irregular in shape, very 

 large, the anterior one larger than the posterior. Anterior testis 

 from about 0.4 to 0.5 mm. in diameter, the posterior one from 0.35 

 to 0.45 mm. ; anterior one slightly to left and posterior one slightly 

 to right, but almost directly one behind the other as seen in lateral 

 view, nearer to ventral side of body. Vas deferens passes from ante- 

 rior margin of posterior testis (connection with anterior testis not 

 seen) in an antero-dorsal direction between the intestinal ceca, turns 

 when near dorsal surface of body, and passes ventrally between intes- 

 tinal ceca just posterior to esophageal bulb. This portion is consid- 

 erably enlarged and serves as a seminal vesicle. Near ventral side 

 of body sperm duct enters a small oval cirrus pouch, measuring 0,17 

 by 0.095 mm., through which it passes and then joins the uterus in 

 a short hermaphroditic duct. Genital opening can be extruded from 

 body, as shown in Figure 4, or withdrawn into a genital cloaca. Ex- 

 cretory pore on dorsal side, a short distance anterior to the posterior 

 sucker. Eggs very large, about 115 to 123ijl by 51 to 57[x. 



Habitat. — Rectum of Amphiuma niea7is, in Louisiana. 



Type. — Deposited in United States National Museum, Helmintho- 

 logical Collections, No. 25173; paratype. No. 25172. 



