PARASITIC FLATWORMS 



437 



42 (43) Cirrus-pouch extends half way across proglottid. 



Proteocephalus exiguus La Rue 191 1. 



Strobila short, slender, length 9 to 38 mm., 

 maximum breadth 0.425 to 0.8 mm. First 

 proglottids longer than broad or nearly quad- 

 rate; mature and ripe proglottids longer than 

 broad, ripe proglottids considerably larger, 0.680 

 to 1. 190 mm. long by 0.460 to 0.59s mm. broad. 

 Sucliers 0.058 mm. broad, 0.069 to 0.085 mm. 

 long. Genital pore near middle of lateral mar- 

 gin of proglottid. Testes 34 to 54 in number, 

 in one layer. Vas deferens forming mass of 

 coils in mid-field. Vagina anterior to cirrus- 

 pouch, crossing it near middle. Uterus with 9 

 to 14 lateral pouches on either side. 



In intestine of Coregonus nigripinnis, C. prog- 

 nathus, and C. artedi, Lake Michigan. 



Fig. 737. Proteocephalus exiguus. a, Head, su, 

 fifth sucker, X 93; b, mature proglottid, X 60 

 (After La Rue.) 



43 (42) Cirrus-pouch less than one-third breadth of proglottid. 



44 (45) Testes in one layer. 



44 

 Proteocephalus pinguis La Rue 1911. 



Strobila short, slender, length up to 

 90 mm., maximum breadth 1.24 mm. 

 First proglottids very short. Mature 

 and ripe proglottids nearly quadrate or 

 in a few ripe proglottids length exceed- 

 ing the breadth. 



Genital pore at or near middle of 

 lateral margin of proglottid. Testes 

 54 to 70, in a single layer. Cirrus- 

 pouch short, stout, 0.13 to 0.14 mm. 

 long by 0.05 to o.o5 nun. broad, i : 3 

 or I : 4 in breadth of proglottid. Va- 

 gina anterior, but vaginal opening al- 

 ways dorsal to cirrus-pouch. Vagina 

 crossing iimer end of cirrus-sheath. 

 Uterus with 10 to 14 lateral pouches 

 on either side. 



In intestine of Esox reticulatus Le 

 Fig 738. Proteocephalus pinguis. a, Head in dorsal or Sueur, and E lucius Lhm., Maine, 



ventral view, X 4S; b, ripe proglottid, utl, lateral uterine Michigan, and Wisconsm. 



pouches, ventral view, X 63. (After La Rue.) 



Proteocephalus pusillus Ward 1910. 



Very small, weak; length 30 to 50 mm., 

 maximum breadth 0.350 mm. Proglottids 

 few. First proglottids broader than long, 

 mature proglottids longer than broad, ripe 

 proglottids much longer (0.84 to 1.4 mm.) 

 than broad (0.18 to 0.35 mm.) 



Genital sinus at end of first one-third to 

 two-fifths of proglottid. Testes 44 to 70 in 

 number, in two layers. Coils of vas deferens 

 few, anterior to cirrus-pouch. Vagina never 

 crossing cirrus-pouch. Uterus with 10 to 16 

 lateral pouches on each side. 



Habitat: Intestine of Salmo seiago Girard 

 and Cristivomer namaycush Walbaum; Se- 

 bago Lake, Maine, Lake Temagami, Ou- 



4S (44) Testes in two layers. 



Fig. 739. Proteocephalus pusillus. a, Head, showing ^^j\q 

 fifth sucker, X 70; b, mature proglottid, toto, X 63. 

 (After La Rue.) 



