43 6 



FRESH-WATER BIOLOGY 



single layer. Vas deferens large mass of coils in mid-field. Cirrus-pouch slender, nearly 

 straight, muscular, length two-fifths to one-third proglottid width. 



Vagina always anterior to cirrus-pouch, never crossing latter. Beginning region of vagina 

 narrow. Uterus with 20 to 25 lateral outpocketings. 



In intestine of Lepisosteus platostomus, Illinois. 



FIG. 735. Proteocephalus singularis. a, Head; apical prominence contracted; b, apical prominence 

 extended, X 50; c, ripe proglottid, frontal section showing arrangements of testes, vitellaria and ovary; 

 vagina and cirrus-pouch not shown, X 36. (After La Rue.) 



40 (39) Suckers round or oval with smooth contour. 



Proteocephalus ambloplitis (Leidy) 1887. 



Large, 280 to 410 mm. long, 2 to 2.5 mm. in maximum breadth. Surface of body rough, 

 with transverse and longitudinal furrows. Scolex prominent. Fifth sucker vestigial. Young 

 proglottids 12 to 15 times broader than long. Mature and ripe proglottids broader than 

 long, about quadrate, or rarely longer than broad. Vitellaria not posterior to lobes of ovary. 

 Genital sinus at end of first fourth of proglottid. Uterus with 15 to 20 lateral outpocketings 

 on each side. Cirrus-pouch pyriform, muscular, two-sevenths to two-fifths of proglottid 

 breadth. Coils of vas deferens many, extending to middle of proglottid. Testes 70 to 100 in 

 number. 



Intestine of Ambloplites rupestris, Micro pterus salmoides, M. dolomieu, Amia calvo,' New 

 York, Michigan, Minnesota, and Wisconsin. 



vas 



FIG. 736. Proteocephalus ambloplitis. a, Head, X 25. (After La Rue); b, ripe proglottid, frontal 

 section showing main parts of male and female reproductive systems, magnified, (After Benedict.) 



41 (34) Well-developed (functional) fifth sucker present 42 



