NEW GENUS AND NEW SPECIES OF TREMATODE 

 WORMS OF THE FAMILY PLAGIORCHIIDAE 



By John T. Lucker 



Junior Zoologist, Zoological Division, Bureau of Animal Industry 

 United States Department of Agriculture 



In 1927, while a student at the University of Washington, the 

 writer collected about 10 flukes from the intestines of frogs {Rana 

 prethsa) . Owing to the lack of adequate library facilities, a de- 

 scription of these parasites, which are regarded as representing a 

 new genus and new species of the family Plagiorchiidae, could not 

 be completed until the writer came to Washington, D. C. A survey 

 of the literature has now made it possible to complete the study of 

 these trematodes and to determine their systematic position. The 

 writer takes pleasure in acknowledging his indebtedness to his asso- 

 ciates in the Zoological Division of the Bureau of Animal Industry 

 for helpful suggestions. The host determination was made by mem- 

 bers of the staff of the Department of Zoology in the University 

 of Washington. 



HAPLOMETRANA, new genus 



Generic diagnosis. — Plagiorchiinae : Slender worms, flattened dor- 

 soventrally, and bluntly rounded at both extremities. Esophagus 

 long and slender. Intestinal ceca long, extending from the bifurca- 

 tion almost to the posterior extremity of the body. The moderately 

 long, slender cirrus pouch extends posterior to the acetabulum and 

 curves about it anteriorly. A saclike seminal vesicle occupies ap- 

 proximately the posterior half of the cirrus pouch, anterior to which 

 are the narrow prostate duct and the ejaculatory duct. The cirrus 

 is protrusible. 



Ha'plometrana may be distinguished from other genera of the 

 subfamily Plagiorchiinae by the possession of a definite combination 

 of characters. The testes are tandem and in the median line. The 

 ovary is approximately median in position, and a seminal receptacle 

 is present. Neither the descending ramus nor the ascending ramus 

 of the uterus passes between the testes. Both branches of the uterus 

 are normally ventral to the testes, and the ascending ramus usually 



No. 2885.— Proceedings U. S. National Museum, Vol. 79, Art. 19. 



59929—31 1 



