70 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



slightly winding tube from genital pore to one half distance to ovary 

 after which it broadens to wide tortuous tube to left of ovary. Cirrus 

 armed with circle of ten short spines with broad bases and fine, 

 sharp recurved points directed toward center of cirrus. Cirrus spines 

 0.006 mm. in length. Genital pore in anterior narrow region of body 

 halfway from anterior end to vaginal opening. Genital atrium with 

 four sets of spines, an incomplete circle of fourteen spines surround- 

 ing anterior end of uterus, 0.016 mm. in length, pointing anteriorly, 

 curved, with distal ends pointing away from center of incomplete 

 circle; two groups of thirty spines each arranged in a curve on each 

 side of genital atrium, 0.012 mm. in length, slightly curved with 

 points directed anteriorly and outward away from center of genital 

 atrium; fourth group attached to cirrus. Vaginal opening dorsal, 

 posterior to bifurcation of esophagus. Vaginal spine imbedded in 

 wall at distal end of vagina not extending through vaginal orifice, 

 0.040 to 0.046 mm. in length by 0.020 mm. in width, slightly bifur- 

 cated at tip. Vaginal canal single, slender, passingly obliquely pos- 

 terior to left from vaginal pore joining middle of left vitelline duct. 

 Ovary U-shaped in anterior third of body in mid-line, right arm 

 broader, anterior end of left arm somewhat lobed. Oviduct arises 

 from right arm of ovary and proceeds anteriorly as in C. cypseluri. 

 Seminal receptacle elliptical, longer than broad to right of mid-line 

 anterior to ovary, 0.152 mm. in length by 0.067 mm. in width. Vitel- 

 laria from vagina on right side and level of bifurcation of esophagus 

 on left to haptor, separated anteriorly and posteriorly. Common 

 yolk duct slender to left of mid-line. Genltointestinal present. Mature 

 eggs not present. 



Comparisons. C. yamagutii difi"ers from C. cypseluri in size, be- 

 ing over twice as long and wide. The region anterior to the vaginal 

 opening is narrower. The ovary is closer to the anterior end. The 

 vaginal spine is slightly shorter and differs greatly in shape, the 

 basal portion is elongated, elliptical rather than spherical. The geni- 

 tal atrium has the same number of groups of spines but their size, 

 number, and arrangement are different, the central group making 

 an incomplete circle as compared with a complete circle. The pos- 

 terior suckers are seventy-five in number compared to forty-one 

 and vary greatly in number and arrangement of skeletal pieces. 



C. yamagutii is named in honor of Professor Yamaguti of Japan. 



