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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 40. 



sparse or altogether absent at the caudal pole. In the median line 

 of the venter, at about the junction of the cephalic with the middle 

 third of the body length, is the circular aperture of the acetabulum. 

 At a point about the acetabular diameter cephalad of the cephalic 



ufc.... 



jC ? 



Fig. 1. — Ventral view showing topography, ac, acetabulum; c. p., cirrus 

 pouch; es., esophagus; ex. p., excretory pore; ex. v., excretory vesicle; 

 g. p., genital pore; »., intestine; L. c, laurer's canal; o. s„ oral sucker; 

 ov., ovary; ph., pharynx; t., testis; ut., uterus; v. g., vitellaria. From a 

 press preparation. Enlarged. Original. 



margin of the acetabulum and in or very slightly to the right of the 

 median line is the genital pore. 



Acetabulum. — The acetabulum varies in diameter in four sectioned 

 specimens between 0.270 and 0.345 mm. It is of a loose-meshed 

 structure like that in Athesmia foxi. 1 Its aperture appears to be 

 somewhat smaller than that of the mouth. 



1 Goldberger and Crane, 1911. 



