526 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



PLATE 55 



Nipporhynchus ornatus (Van Cleave) and Centrorhynchus spinosus (Kaiser) 



Fig. 18. N. ornatus, posterior extremity of male showing relations of 

 testes, four cement glands, and everted bursa. 



Fig. 19. C. spinosus, entire immature male showing differentiation of 

 bodily regions. 



Fig. 20. C. spinosus, proboscis of mature female and associated 

 structures in anterior region of body. 



