184 PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 101 



Luiens lubens (Braun, 1901) Strom, Parasitol. Sborn. Zool. Inst. Acad. Nauk 

 U. S. S. R., vol. 8, p. 180, 1940. 



Description.— Body thick and broadly oval, tapering toward ex- 

 tremities, measuring 5.36 to 5.64 mm. long by 2.25 to 2.64 mm. wide, 

 widest near posterior end of vitellaria. Cuticle thick, without spines, 

 transversely wrinkled, and with retractile sensory papillae on the 

 preacetabular margins of body. Oral sucker muscular, subterminal 

 in position, oval in shape and measuring 0.42 to 0.47 mm. in diameter. 

 Acetabulum muscular, 0.42 to 0.50 mm. in diameter, situated relatively 

 close to oral sucker within anterior fourth of body. Katio of sucker 

 diameters about 1 : 1. Pharynx large, globular, 0.16 mm. long by 0.19 

 to 0.21 mm. wide. Esophagus short, straight, approximately equal 

 in length to pharynx. Intestine bifurcating at approximately two- 

 thirds the distance from oral sucker to acetabulum. Ceca narrow, 

 slightly sinuous, passing dorsal to lateral margins of testes and 

 medial margins of vitellaria to terminate about midway between ends 

 of vitellaria and posterior end of body. Excretory pore terminal. 

 Excretory vesicle tubular and voluminous, extending anteriad to about 

 equator of body where it receives a common collecting tubule from 

 each side of body. Each common collecting tubule passing antero- 

 lateral to posterior level of testes where it divides into an anterior and 

 posterior main collecting tubule. Genital pore median, at posterior 

 level of pharynx. Testes rounded, approximately equal in size, 0.30 to 

 0.50 mm. in diameter, situated directly opposite each other, lateral to 

 the acetabulum with their zones lying almost entirely within that of 

 acetabulum. Cirrus sac small, club-shaped, 0.38 mm. long by 0.11 

 mm. wide (single specimen), extending slightly posterior to intestinal 

 bifurcation, containing convoluted seminal vesicle, prostatic gland 

 cells, and eversible cirrus. Ovary rounded, 0.28 to 0.43 mm. in diameter 

 situated either to right or left side of body close behind the respective 

 testis. Seminal receptacle small, situated dorsal to posteromedial 

 margin of ovary. Mehlis' gland diffuse, located ventral to medial 

 margin of seminal receptacle. Vitellaria composed of numerous oval 

 follicles, situated in lateral margins of body, extending posteriorly 

 from within zone of acetabulum for a distance of 2.67 to 2.96 mm. 

 (or about half the total body length). Vitelline ducts arising at 

 point approximately midway the vitellaria. Uterus very voluminous 

 and greatly convoluted, filling most of postacetabular region of body 

 and sending characteristic loops lateral to testes to anterior level of 

 acetabulum before following a wavy course to genital pore. Mature 

 ova numerous, dark brown, 26/^ to 31/* long by 17/x to 23^i wide, fully 

 embryonated when oviposited. Miracidium symmetrical, ciliated, 

 possessing a stylet and having two large oval oppositely situated 



