4 SMITHSONIAN ^f TSCELLAXEOUS COLLECTIONS VOL. qi 



level of center of acetabuhim. Genital aperture to left of acetabulum : 

 genital sitnis relatively lar^c and containing a])i)arent1y three papilla- 

 like processes. .Seminal vesicle lari^e. semilunar in shape, filling greater 

 part of space between acetabulum and intestinal ceca. Testes globu- 

 lar, about 28 /i in diameter, with zones coinciding and fields widely 

 separated, situated ]>osterior to acetabulum. Ovary transversely oval, 

 about 18 fx long by 22 /x wide, i:)retesticular and to right of acetabulum. 

 Vitellaria posttesticular, situated dorsal to uterine coils and consisting 

 of two groups of five to six follicles each. Uterus postacetabular and 

 largely posttesticular. Eggs oval, 2T.6 /jl long by 12.6 // wide. 



Host. — Nyroca affinis. 



Location.— SnvdW intestine. 



Type locality. — b'lamingo Lake, Culebra Island. West Indies. 



Type specimens. — L'.S.N.M. Hehu. Coll. no. 8703 ; paratypes 

 no. 8704. 



This is the smallest si>ecies of the genus and perhaps the smallest 

 known trematode. It resembles Lcvinseniclla clavifoniie (Brandes) 

 as described by Nicoll (1909) more than any other member of the 

 genus, but may be distinguished from that species by its almost 

 triangular shape, absence of prepharynx, shorter esophagus, longer 

 intestinal ceca. and fewer eggs. 



Family STRIGElDAh: 



Subfamily CYATHOCOTYLINAE 



PROHEMISTOMUM FAJARDENSIS, n. sp. 



Plate I, fig 6 



Description. — ^rV)dy scoop-shaped. 1.105 to 1.360 mm long, divided 

 into a widened anterior part 1.071 mm long by 0.51 to 0.795 '''^'^^ wide 

 and a short, dorsally directed, appendixlike posterior part 85 to i75 /* 

 long by 160 to 204 /x wide. (3ral sucker subterminal 52 to 60 /u, in 

 diameter ; acetabulum 64 to 80 jx in diameter ; adhesive organ slightly 

 oval in outline, 320 to 400 /x long by 300 to 320 fx wide, with deep 

 central depression. Pharynx 32 to 40 fx long by 24 to 35 /x wide ; 

 esophagus short ; intestinal ceca slender, extending to junction of 

 anterior and posterior parts of body. Genital aperture at posterior 

 end of body, subterminal, directed dorsally ; genital sinus spacious. 

 Cirrus pouch slender, about 380 /x long by 80 fj. wide at base, extending 

 either to right or left around testes and ovary, its base lying in zone 

 of anterior testis, and containing a seminal vesicle, prostate and 

 cirrus. Testes globular or slightly oval, with zones separated and 

 fields partly coinciding; anterior testis 120 to 140 /x long by 112 to 



