402 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



nal, funnel shaped, longer than wide, length 0.240 to 0.314, width 0.202 

 to 0.272. Acetabulum about Y^ body length from anterior end, 0.107 to 

 0.126 in diameter or about half the transverse diameter of oral sucker. 

 Prepharynx present, almost as long as pharynx, pharynx well developed, 

 0.117 to 0.130 long by 0.080 to 0.118 wide; esophagus not quite so long 

 as pharynx; ceca extending to near posterior end of body. Genital pore 

 median or submedian, a very short distance anterior to acetabulum. Testis 

 large, ovoid, intercecal, directly posterior to midbody. (Two vasa effer- 

 entia could be seen arising from the anterior end of the testis in one speci- 

 men.) Cirrus sac elongate, curving around the right side of acetabulum 

 or overlapping the right half of acetabulum, extending to the anterior 

 edge of the ovary or even past the ovary to the anterior edge of the testis ; 

 containing a long-spined cirrus, pars prostatica, prostate gland, and, in its 

 basal third, the ovoid seminal vesicle. Spines in the cirrus are of one type. 

 Ovary ovoid, unlobed, immediately anterior to testis, to the right. Semi- 

 nal receptacle, if present, rudimentary. Vitellaria of 9 large, distinct 

 follicles on each side, lateral, just posterior to midbody at ovariotesticular 

 level. Uterus chiefly intercecal, filling most of hindbody, entering the 

 middle region of the metraterm sac. Metraterm sac elongate oval, to the 

 left, extending a short distance posterior to the acetabulum, containing a 

 large spherical vesicle in its base and an anterior spiny region. What 

 seems to be a muscular terminal region is probably the genital atrium but 

 is not demarked from the metraterm. Eggs 18 to 20 by 9 to 11 p.. The 

 excretory system could not be made out. 



Comparisons. This species is probably most closely related to Procto- 

 trema truncata (Linton, 1910) n. comb.^ (Synonym: GcTiolopa truncata 

 Linton), but is clearly distinct in the following characters: more elongate 

 body, much longer ceca, more slender cirrus sac, smaller ovary, more pos- 

 terior vitellaria, larger acetabulum, and slightly larger eggs. P. longicae- 

 cum differs from P. bacilliovatiim Odhner, 1911 in shape of eggs as well 

 as in other characters; from P. lintoni Manter, 1931 in body form, size of 

 oral sucker, extent of ceca, more posterior vitellaria, more slender cirrus 

 sac, and shorter eggs. It differs from P. plectorhynchi Yamaguti, 1934 in 

 shape of ovary, length of ceca, more slender cirrus sac, and smaller eggs. 

 It differs from P. macrorchis Yamaguti, 1934 in longer ceca, shape and 

 position of ovary, and smaller eggs. 



1 The removal of Genolopa truncata from the genus Genolopa leaves Geno- 

 lopa ampullacea, the type species, still in the genus which is at least for the present 

 recognized as distinct from Proctotrema. 



