68 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



nal opening a short distance, 0.048 mm. in length by 0.018 to 0.020 

 mm. in diameter at base, with broad spherical base and tapering 

 distally to outer distal tip which is bifurcated. Vaginal canal, single, 

 slender, extending from vaginal opening obliquely posterior to the 

 left and joining left vitelline duct. Ovary U-shaped, right arm almost 

 twice as long as left arm, just anterior to middle of body in mid- 

 line. Oviduct arises from right arm of ovary, is joined by common 

 yolk duct near ovary, passes anteriorly to right of mid-line where 

 it receives openings of seminal receptacle and genitointestinal be- 

 fore joining upper end of common yolk duct on right side. Seminal 

 receptacle elliptical, relatively large, twice as long as wide, to right 

 of mid-line anterior to ovary, 0.108 to 1.120 mm. in length by 0.520 

 to 0.060 mm. in width. Vitellaria from vaginal canal on right side 

 and level of bifurcation of esophagus on left to haptor, separated 

 anteriorly and posteriorly. Common yolk duct elongated, sac-like, 

 to left of mid-line. Genitointestinal canal present. Mature eggs not 

 present. Large cells on each side of genital pore for which the author 

 proposes the name giant cells (fig. 75), three pairs extending from 

 brain to bifurcation of esophagus, from one fourth to one third width 

 of animal at level of genital pore. 



C. cypseluri is named after the genus of its host, Cypselurus. 



GENERIC DIAGNOSIS OF CESTRACOLPA 



Body elongated, slender anteriorly, truncate posteriorly, asym- 

 metrical due to unusual development of one side of posterior haptor. 

 Long side of diagonal posterior haptor bears numerous (sixty to 

 100) suckers in a single row. No chitinous hooks at posterior end of 

 body. Vaginal opening single, lateral. Vaginal canal single, bearing 

 conspicuous spine at distal end. Genital spines in four groups, one 

 anterior, one posterior, and two lateral. Testes numerous posterior 

 to ovary. Mouth subterminal, ventral. Mouth cavity with a pair of 

 elliptical suckers. Three pairs of giant cells on each side of genital 

 pore. The giant cells on each side of the genital pore seem to be 

 unique. The common yolk duct is enlarged, sac-like, and extends 

 posteriorly to left of mid-line but instead of joining the oviduct at 

 the posterior end it joins it at the anterior end. The vagina arises 

 from the yolk duct on the right side just before the two yolk ducts 

 unite. The four groups of genital spines, three groups associated 



