444 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



developed, thin walled, nonmuscular, 0.076 by 0.019, containing very 

 few prostatic cells. Male pore dorsal, to the right, a little posterior to 

 lateral lobe of body. Ovary median, consisting of 2 fan-shaped lobes, 

 a short distance anterior to lateral indentation of body; more or less 

 porous and meshlike (as in some cestodes). Oviduct straight, extending 

 directly backward to a level opposite male pore where it is joined by 

 the single yolk duct ; middle region of oviduct swollen to form a seminal 

 receptacle (fig. 135). After union with vitelline duct the oviduct turns 

 forward and enlarges to form the ootype. Mehlis' gland not clearly 

 delimited but perhaps represented by glandular cells filling much of 

 posterior end of body. Uteiais postovarian with broad ascending limb and 

 smaller descending coils. Uterine pore ventral, to the right, anterior to 

 lateral indentation, postovarian. Eggs fairly numerous, very thin shelled, 

 broadly ovoid, 29 to 32 by 18 to 20 /x. Vitellaria of small spherical 

 masses chiefly between ovary and intestinal bifurcation ; a few follicles 

 extending along each side of esophagus as far as the nerve commissure; 

 not extending posterior to ovary. Excretory pore terminal; excretory 

 vesicle not traced. 



The name tropicum is for the region where the parasite was collected. 



Discussion. P. tropicum differs from P. japonicum (Goto and Ozaki, 

 1929), the only other species in the genus, in its longer esophagus, less 

 extensive vitellaria, more slender body, bilobed ovary, weaker cirrus sac 

 of different shape, and larger seminal vesicle. The bilobed ovary of P. 

 tropicum suggests the genus Sanguinicola but the genital pores are post- 

 ovarian. P. japonicum is from a related host as is also another related 

 species Paradeontacylix odhneri (Layman, 1930) Mcintosh, 1934. 



The genus Psettarium was named by Goto and Ozaki in 1930 for 

 the genus Plehnia Goto and Ozaki, 1929, the name of which was pre- 

 occupied. Its type species thus became Psettarium japonicum (Goto and 

 Ozaki, 1929). Mcintosh (1934) described the genus Paradeontacylix 

 for a species of blood fluke (P. sanguinicola) from Seriola lalandi. He 

 also transferred Aporocotyle odhneri Layman, 1930 to Paradeontacylix. 

 Although Paradeontacylix was not compared with Psettarium, Mcintosh 

 in correspondence with the writer considers the reticular structure of the 

 testis in Psettarium a generic character separating the two genera. 



The family Aporocotylidae contains the following genera: Aporo- 

 cotyle Odhner, 1910; Sanguinicola Plehn, 1905 (synonym, as indicated 

 by Mcintosh, Janickia Rasin, 1929) ; Deontacylix Linton, 1910; Pset- 

 tarium Goto and Ozaki, 1930; and Paradeontacylix Mcintosh, 1934. 



