386 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



that p. breviformts has a much shorter cirrus sac not much more than 

 reaching the acetabulum, a shorter esophagus, smaller and wider eggs, 

 more tapering hindbody, and longer posttesticular space. 



Discussion. Park (1937) has recently reviewed the genus Podocotyle. 

 In view of his emphasis on the form of the seminal vesicle it might be 

 stated here that in P. pearsei Manter, 1934 the seminal vesicle is largely 

 a straight wide tube filling most of the cirrus sac but which after narrow- 

 ing loops back a short distance and then becomes slightly sinuous. Thus, 

 the species is correctly placed in Park's key under the head of "seminal 

 vesicle sinuous." The distinction, however, between a "sinuous" and a 

 "coiled" seminal vesicle might be difficult to determine. Park questioned 

 the specific value of the length of the esophagus, extent of vitellaria, and 

 size of eggs within this genus. Obviously, such characters should be care- 

 fully evaluated with some consideration given to degree of body contrac- 

 tion or extension. Single specimens may exhibit abnormal or unusual con- 

 ditions which should not influence specific criteria too much. In general, 

 the writer feels that length of esophagus, extent of vitellaria, and size of 

 eggs are fairly reliable specific characters in this genus. 



Park (1937a, p. 411) states that "size of eggs is the only reliable dif- 

 ference between P. levinseni (= the P. levenseni of Park, 1937) and P. 

 pearsei, and then concludes that P. pearsei can scarcely be established as 

 distinct from P. levinseni. While this conclusion may be correct, differ- 

 ences between the 2 forms include not only the size of the eggs but also 

 the shape of the eggs and the anterior extent of the vitellaria (as used by 

 Park in his key). 



P. pacifica Park, 1937 seems to be very similar to the P. atomon of 

 McFarlane, 1936 which was collected from a similar host from a neigh- 

 boring region. The esophagus of the specimen drawn by McFarlane is 

 short for P. atomon; yet the vitellaria are too continuous for P. olssoni. 

 Collections of these 2 Pacific forms should be compared more fully. 



Helicometra torta Linton, 1910 



Host: Epinephelus labriformis (Jenyns) 

 Location: Intestine 

 Locality: Cape Elena, Ecuador 

 Number : 5 specimens in one host 



These trematodes agree fully with H. torta in all fundamentals such 

 as size, thin hindbody, sucker ratio, position of genital pore, aperture of 



