580 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io8 



circular fibers. Distally the wall thins and the vesicle then makes a 

 sharp bend, diminishing abruptly to a narrowed tube with thin mus- 

 cular wall that parallels the thick muscular part. This tube then 

 bends again and as a narrowed duct runs close to the oval prostatic 

 vesicle, eventually coming in contact with the prostatic duct. The 

 two ducts run in contact for some distance, then fuse to form an 

 ejaculatory duct that passes to the surface. Seminal and prostatic 

 vesicles are imbedded in a muscular area indicated by a dotted line 

 in figure lie. The ejaculatory duct could not be traced into the 

 penis papilla, a nonmuscular conical elevation occupjdng a broad 

 shallow male antrum and apparently devoid of the usual penis stylet 

 characteristic of the Cotylea. 



All eight female apparatuses are approximately identical and one 

 of them is shown in sagittal view in figure lib. The gonopore leads 

 into a deep tubular female antrum having the same histological con- 

 struction as the adjacent body wall. It is lined by an epithelium of 

 tall narrow cells underlain by the usual muscle stratum. At its 

 internal end the antrum enters the cement pouch of the vagina but 

 the epithelium here appeared disrupted, whether normally or as a 

 failure of fixation is not determinable. The cement pouch and the 

 glandular tubular vagina leading inward from it receive a tremendous 

 mass of cement glands on all sides. The vagina then expands and its 

 wall, very thin in the glandular region, widens to a cuboidal epithe- 

 lium of loose texture. The vagina then makes a bend, forward in 

 some of the apparatuses, backward in others, and approaches a large 

 cavity filled with eggs that appears to be a median uterus. Seem- 

 ingly this species has a single median uterus in which the eggs collect 

 rather than the usual paired uteri. All eight vaginas are directed 

 towards this median uterus but none could be followed directly into 

 it although some contained an egg or two. The uterus is bounded 

 by a definite epithelial wall in which no openings could be found. 

 However, one must suppose that, at the time of spawning, eggs are 

 discharged from the uterus through all eight vaginas and out of all 

 the gonopores. The absence of a sucker is presumably associated 

 with the multiplication of female apparatuses that extend into the 

 area where the sucker would normally occur. 



Holotype: The larger specimen (USNM 28660) in alcohol is made 

 the holotype, plus the removed anterior median part as sagittal serial 

 sections (31 slides). 



Remarks: The multiplication of male apparatuses is common in 

 polyclads but the multiplication of female apparatuses is rare. Apart 

 from anomalies the only comparable case of which I know is that of 

 Cestoplana polypora Meyer (1921), in which also there is present a 

 midventral longitudinal row of female apparatuses ranging in number 



