18 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 81 



HAEMATOLOECHUS UNIPLEXUS, new species 



Plate 2, Figxjre 1 



Specific diagnosis. — Haematoloechus : The body is an elongated 

 oval, slightly pointed at the anterior end. It measures 4.25 by 0.7 

 nim. The cuticula is smooth and without spines. The oral sucker 

 is 0.22 mm in diameter. Its ratio to the pharynx is as 2 : 3, and its 

 ratio to the acetabulum is close to as 1 : 3. The pharynx is 0.14 

 mm in diameter, and the acetabulum is 0.08 mm in diameter. The 

 length of the esophagus is equal to about two-thirds the diameter of 

 the pharynx. From it the intestinal ceca extend to the posterior 

 end of the body. The ovary lies beside the acetabulum. It is an 

 elongate, irregularly lobed structure with its long axis parallel to 

 the long axis of the body. The uterus, after a few folds just ante- 

 rior to the ovary, turns toward the posterior end. It follows the 

 usual course with the usual confusion of loops and windings to the 

 posterior end of the body. The longitudinal folds outside of the 

 intestinal ceca are very poorly developed. There is a short loop on 

 the left side of the body extending only to the caudal margin of the 

 posterior testis. There is no loop of the uterus on the right side 

 of the body. From the posterior end of the body, the uterus fol- 

 lows the usual course forward to the genital pore, which lies in the 

 pharyngeal region. The vitellarian follicles are so closely grouped 

 that it is very difficult to form an accurate opinion of the number 

 of follicles to the group. There seem to be 9 or 10 follicles to the 

 group and about 21 groups. On the left side of the body the follicles 

 cease at the level of the cephalic margin of the caudal testis. On 

 the right side there are three groups of follicles, below this point. 

 The eggs vary from 21/a by l7/x to ITyu, by 13/x. The testes are 

 elongate bodies, with entire margins that overlap slightly. The 

 anterior testis measures 0.5 by 0.16 mm and^the posterior one 0.48 

 by 0.16 mm. The caudal testis is somewhat more than its own 

 length from the caudal tip of the body. The seminal vesicle lies 

 beside the ovary. The length of the genital field, exclusive of the 

 vitellaria, equals slightly more than one-third of the total body 

 length. 



Host. — Ran a sphenoce'phala. 



Locality. — Houston, Tex. 



Habitat. — Lung. 



Type specimen.— V.^:^M. Helm. Coll. No. 30880. 



Retnarks. — This form closely resembles Haematoloechus floedae 

 described above, but it is easily distinguished from that form by the 

 short longitudinal uterine loop, of which there is only one, its un- 

 symmetrical character, the ratio between the oral sucker and the 

 acetabulum, and the position of the testes relative to each other. 



