I>LATE XXIII—Continued. 
Phoetus Prouti 
Fig. 16. 
Fig. 17. 
Fig. 18. 
Fig. 19. 
Fig. 20. 
Fig. 21. 
Fig. 22. 
Fig. 23. 
Fig. 24. 
Fig. 25. 
Fig. 26. 
Fig. 27. 
Fig. 28. 
Fig. 29. 
Fig. 30. 
Fig. 31. 
Fig. 32. 
Page 126. 
A nearly entire individual from which a portion of the side of the cephalon and thorax has been 
bi’oken away. 
A pi-ofile of the same, showing the elevation of the body. 
Hamilton group. Smith's q^iarry, Davenpm-t, Imoa. 
An impei'fect individual, showing the axial nodes on the posterior thoracic segments. 
Hamilton group. Cook's quarry, Davenport, Iowa. 
The specimens represented in these two figures are the originals of Droetus Davenjwrtensis, 
Harris. 
Pkoetus NkVAD/E. 
Page 129. 
A nearly entire individual, showing the elongate body, narrow glabella and small eyes. 
Devonian limestones. Comb's Peak, Eureka District, Nevada. 
l^ROETUS ROWI, 
Page 119. 
See Plate 21. 
A large entire individual. 
Hamilton gi’oup. Centerjield, Ontario county. 
A somewhat imperfect siiecimen, retaining the crust and showing the glabellai- furrows. 
Hamilton group. Eighteen-mile Creek, Erie county. 
A smaller, nearly entire individual. 
Hamilton group. Centerfield, Ontario county. 
A young individual, showing the very large eyes. 
Hamilton group. Centerjield, Ontario county. 
A still younger example. 
Hamilton group. Centerjield, Ontario county. 
A small individual in which two of the thoracic segments have been pushed foi-ward beneath the 
cephalon. 
Hamilton group. In the drift, A7in Arbor, Michigan. 
Two entire individuals of average size. 
Hamilton group. Centerjield, Ontario county. 
The specimen figured on plate 21, fig. 25, drawn natural size. 
Tully limestone. Near Ovid, Seneca county. 
A small individual, retaining a poi-tion of the test and showing the essential features of the species. 
Tully limestone. Near Ovid, Seneca county. 
An hyj)Ostoma. 
Hamilton group. Centeijield, Ontario county. 
Pkoetus macrocephalus. 
Page 116. 
See Plate 21. 
A nearly entire individual. 
Hamilton group. Canandaigua Lake. 
The pygidium of a very large example. 
Hamilton grouji. CaJMndaigua Lake. 
Pkoetus Missouriensis. 
Page 133. 
A portion of the cephalon. 
This specimen is the original of Proetus auricndatus. Hall (Fifteenth Kept. N. Y. State Cab. Nat. 
Hist., p. 107, 1862), from the Waverly group. Licking county, Ohio. 
