562 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 108 



teeth are definitely not folds, and Lang's vesicle is rather short. 

 The descriptions of P. langi and P. rotumanensis do not mention the 

 presence of accessory prostatic vesicles or male antral glands but 

 these structures cannot be presumed to be absent. P. fritillata 

 appears to differ from previously described species of the genus in 

 the very strongly differentiated cement pockets, one from the anterior, 

 the other from the posterior side of the vagina. There is no pocket 

 associated with the entrance of the bursa into the vagina as de- 

 scribed for P. misakiensis Yeri and Kaburaki (1918). These cement 

 pockets, the cloud of black dots, the poor differentiation of the ac- 

 cessory prostatic vesicles, the lack of spination of the anterior part 

 of the cirrus sac, and the short Lang's vesicle may be taken to charac- 

 terize P. fritiUata. 



Holotype: USNM 28649, one whole mount with copulatory 

 region removed and sectioned (four slides). 



Family Callioplanidae Hyman, 1953 

 Asoleniaf new genus 



Definition: Callioplanidae without Lang's vesicle; reduced female 

 tract enters the roof of the male antrum; male copulatory apparatus 

 as in Callioplana. Type species: Asolenia deilogyna. 



Asolenia deilogyna, new species 



Figure 6b,c 



Material: One specimen collected from algae at the Palau 

 Islands by the Stanford team July 22, 1955, Sta. 30. 



General characters: This is a very small worm, 2.5 mm. long, 

 colorless, without tentacles, of a moderately elongated shape (fig. 

 66). The eyes are rather few in number, arranged in an arc of about 

 a dozen eyes on each side (fig. Qb) ; in this arc, four larger eyes on 

 each side probably represent tentacular eyes. The central ruffled 

 pharynx is encircled anteriorly by the confluent uteri, fiUed with eggs, 

 and ovaries are seen scattered in lateral regions. At first the specimen 

 was thought to be a juvenile leptoplanid but then the uteri were 

 noticed, evidencing sexual maturity. 



Copulatory apparatus: Because of its small size the entire worm 

 was sectioned sagittally. Examination of the sections revealed sur- 

 prisingly a member of the family Callioplanidae. A sagittal view of 

 the copulatory complex is given in figure 6c. The male complex is 

 well developed and clearly shown on the sections. The oval free 

 prostatic vesicle with muscular wall of moderate thickness and glan- 

 dular eosinophilous interior is in contact on its ventral side with an 

 elongated, oval seminal vesicle with muscular wall. The duct of the 



