354 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



side of ovary or even posterior to it. Uterus preovarian ; metraterm long, 

 sinuous, dorsal to acetabulum and to anterior half of cirrus sac. Vitellaria 

 from mid-acetabular level to posterior end of body; dorsal, ventral, lat- 

 eral, and partly median to ceca. Eggs thin shelled, 60 to 75 by 32 to 42 /a. 

 Excretory vesicle extending to intestinal bifurcation. 



Type host: Mycteroperca xenarcha 



Comparisons. This species differs from all others in the genus, ex- 

 cept L. nicolli Manter, 1935, in its very short esophagus. It is very similar 

 in most other respects to L. nicolli, e.g. extent of vitellaria, size of eggs, 

 position of testes, sucker ratio. It is not thought to be L. nicolli chiefly 

 because in every specimen the external seminal vesicle reached to or nearly 

 to the ovary, whereas in all 3 specimens of L. nicolli this organ only 

 reached about halfway between acetabulum and ovary. Other differ- 

 ences shown by L. hancocki are : more anterior genital pore ; longer, more 

 sinuous metraterm ; narrower forebody ; and a constantly different shape 

 of the internal seminal vesicle, which is small and spherical in L. nicolli. 



The species is named in honor of Captain Allan Hancock. 



L. hancocki occurred in each case with Prosorhynchus pacificus, and 

 each collection of the latter was from a host infected with the former. 



Lepidapedon nicolli Manter, 1934 



Host: Unidentified, spotted grouper 

 Location : Ceca 



Locality: Isabel Island, Mexico 

 Number: One specimen 



Although but one specimen was collected, comparison with the de- 

 scription and with paratype specimens of L. nicolli makes its identifica- 

 tion definite. It agrees in every detail of structure and size except for 

 slight variation in that the seminal vesicle extends more than halfway to 

 the ovary and the eggs reach only a size of 58 by 36 /x. However, the 

 former character is more or less variable in the 3 specimens of L. nicolli, 

 and additional egg measurements of L. nicolli show that its eggs may be 

 as small as 56 by 35 fx. The most characteristic feature of the species is 

 the position of the genital pore posterior to the anterior border of the 

 acetabulum. The original description states the genital pore to be "at 

 level of anterior border of ventral sucker or slightly posterior to this 

 level." In the Pacific specimen and in one Atlantic specimen the pore is 

 actually about opposite the middle of the acetabulum. 



L. hancocki is a very similar species, but the genital pore is definitely 

 anterior to the acetabulum. 



