320 ILLINOIS BIOLOGICAL MONOGRAPHS [320 



EXPLANATION OF PLATE 



Fig. i. — Proteocephalus macrocephalus (Creplin), head, toto. Lot 71, Sebago 

 Lake. Ward Collection. 



Fig. 2. — Proteocephalus pusillus Ward, head, toto, showing fifth sucker. From 

 Cristivomer namaycush, Lake Temagami. 



Fig. 3. — Proteocephalus pusillus Ward, head, toto, showing fifth sucker. From 

 Sal 1110 sebago, Sebago Lake. 



Fig. 4. — Proteocephalus pusillus Ward, head, toto, showing fifth sucker. From 

 Cristivomer namaycush, Lake Temagami. 



Fig. 5. — Proteocephalus cernuae (Gmelin), head, toto. From lot 09.26 Ward 

 Collection. 



Fig. 6. — Proteocephalus cernuae (Gmelin), head, toto. From lot 09.26 Ward 

 Collection. 



Fig. 7. — Proteocephalus torulosus (Batsch), head, toto, a characteristic shape. 



Fig. 8. — Proteocephalus percae (Midler), head, toto. From lot 10.122 Ward 

 Collection. 



Fig. 9. — Proteocephalus percae (Midler), head, toto. From lot 10.123 Ward 

 Collection. 



Fig. 10. — Ophiotaenia perspicua La Rue, head, toto. 



Fig. 11. — Ophiotaenia calmettei (Barrois), head, toto. 



Fig. 12. — Crepidobothrium gerrardii (Baird), head, toto. From lot 08.472 

 Ward Collection. 



Fig. 13. — Crepidobothrium gerrardii (Baird), head, toto. From lot 10.190 

 Ward Collection. 



