129] PROTEOCEPHALIDAE—LA RUE 129 



is approached in size only by P. longicollis. The latter, however, has 

 a well developed fifth sucker and, according to von Linstow, a much 

 smaller number of testes. P. torulosus may be differentiated from P. 

 percae and P. cernuae by its larger head, larger suckers, lack of a fifth 

 sucker, more numerous testes and the different arrangement of the same, 

 and by its smaller number of uterine pouches. P. torulosus is much 

 larger than P. macroccphalus. It hds a larger head, larger suckers, 

 fewer uterine pouches and a different arrangement of the dorsal layer 

 of testes than the latter species. P. torulosus is so different from the 

 other described species of Proteocephalus that a danger of its being 

 confused with them is scarcely possible. 



'i 

 PROTEOCEPHALUS MACROCEPHALUS (Creplin) 



[Figs. 1, 47-49, 171] 



Specific Diagnosis: The characters of the genus. Adult cestodes 

 possessing strobila as much as 40 cm. long by 1-1.8 mm. broad or per- 

 haps more. Segmentation quite distinct. Proglottids very numerous; 

 first much broader than long; mature, broader than long or nearly 

 quadrate ; ripe, longer than broad. Neck 5.0-7.0 mm. long, 0.1-0.25 mm. 

 broad. Head globose, flattened dorsoventrally, 0.28-0.30-0.32 mm. broad, 

 0.15-0.16 mm. thick. Suckers 0.095-0.106 mm. in diameter. Fifth 



