Phagoaata oregonensis Hyman, 1963 



Synonym: Fontioola oregonensis: Ball, 1969 



28 rri 29 . 



O.Smm 



ph m b 



pi vd am ode gp 



Fig. 29 after Kenk (1970a), 



A small, white species up to 8 mm long and 1.5 mm wide. Head truncate, 

 frontal margin with slightly protruding central and lateral portions. 

 Lateral edges rounded, extending laterally, causing a constriction to 

 appear behind the head. Eyes usually two, but smaller supernumerary eye 

 spots are not rare. The distance between the two principal eyes is 1/5 

 to 1/4 the width of the head at eye level, their distance from the frontal 

 margin greater than from the lateral margins. The tip of the anterior 

 intestinal ramus is behind the level of the -syes. Externally similar to 

 the Alaskan P. nivea and the eastern P. morgani. Testes ventral, extend- 

 ing posteriorly behind the copulatory complex (in P. morgani only to the 

 level of the mouth). Penis consists of a medium size bulb and a short, 

 conical, pointed papilla. The sperm ducts, after expanding at the sides 

 of the pharynx as spermiductal vesicles, continue posteriorly to the level 

 of the male atrium, then turn forward again to enter the penis bulb later- 

 ally. They open into the penial lumen independently, without first unit- 

 ing. The lumen is an elongated cavity, not differentiated into seminal 

 vesicle and ejaculatory duct, and opens at the tip of the penis papilla. 

 The openings of the common oviduct and of the canal of the copulatory 

 bursa are close to the gonopore. No common genital atrium is developed. 

 Known only from a spring in Portland, Oregon. Literature: Hyman (1963), 

 Kenk (1970a). 



32 



