^EXPLANATION OF PLATE XXII. 



Figures 1-4 CORYDOCEPHALUS PHLYCTAINODES Greene... p. 234 



. 1, Dorsal view of a slightly distorted cranidium preserving 

 some of the spines, from near Lemont. (Pal. Coll. Walker 

 Museum, No. 10,741, Collected by J. H. Handwerk.) 2, Dor- 

 sal view of a nearly complete pygidium, from near Lemont. 

 (Pal. Coll. Walker Museum, No. 10,743.) v 3-4, Dorsal and 

 lateral views of a nearly complete cranidium, from near , 

 Lemont. (Pal. Coll. Walker Museum, No. 10,742.) 



Figures 5-7 DICRANOPELTIS NASUTA n. sp p. 240 



5-6, Lateral and dorsal views of an incomplete cranidium. 7, 

 Ventral view of the anterior portion of another incomplete 

 cranidium. Both specimens from Milwaukee, Wis. (Col- 

 lection of Mr. E. E. Teller.) 



Figures 8-9 -DICRANOPELTIS TELLERI n. sp p. 241 



Dorsal and lateral views of the type specimen, a nearly com- 

 plete cranidium, from Milwaukee, Wis. (Collection of Mr. 

 E. E. Teller.) 



Figures 1011 DICRANOPELTIS DECIPIENS W. & M p. 237 



10, Dorsal view of an incomplete cephalon, restored in out- 

 line, from near Lemont. (Pal. Coll. Walker Museum, No. 

 9,876. Collected by L. H. Hyde.) 11, Dorsal view of a 

 nearly complete pygidium, from Hawthorn. (Pal. Coll. 

 Walker Museum, No. 8,610. Collected by G. H. Harris.) 



Figures 1213 METOPOLICHAS FERRISI n. sp p. 244 



12, Dorsal view of an incomplete cranidium. 13, Dorsal 

 view of a nearly complete pygidium. Both specimens from 

 near Channahon, Will Co., 111. (Pal. Coll. Walker Museum, 

 No. 10,737.) 



Figure 14. ARCTINURUS CHICAGOENSIS n. sp p. 248 



(See also Plate XXIII., Figs. 7-8.) 



A nearly complete hypostome believed to belong to this species,- 

 from Hawthorn. (Pal. Coll. Walker Museum, No. 10,744, 

 Van Home Collection.) 



