North American Patseozoic Crustacea. 31 



Seelyi, Whitfield, 1889 ; Bull. Am. Miis. Nat. Hist. New York, vol. 2, p. 60, 

 pi. 13, figs. 15-21. Calciferous. 



Protobalanus, Whitfield, 1888 ; Pal. New York, vol. 7, p. 209 ; Bull. Am. 

 Mus. Nat. Hist. New York, vol. 2, 1889, p. 66. ^ 



Diaynosis. — Shell ovate about the base ; composed of 12 plates of which 

 the carina is largest and most elevated. Rostrum small ; lateralia 

 five on each side ; radial areas between the lateralia broad ; scutum 

 and tergum not known. General surface depressed convex. (Hall and 

 Clarke, 1888 ; Pal. New York, vol. 7, p. Ixii.) 



Hamiltonensis (Whitfield), Hall & Clarke, 1888 ; Pal. New York, vol. 7, 

 p. 209, pi. 36, fig. 23. Hamilton. 



Hamiltonensis, Whitfield, 1889 ; Bull. Am. Mus. Nat. Hist. New York, 

 vol. 2, p. 67, pi. 13, fig. 22. Marcellus Shales. 



Protocaris, Walcott, 1884 ; Bull. U. S. Geol. Survey, No. 10, p. 50. 



Diagnosis. — " Carapace without evidence of a dorsal suture, rounded on 

 the dorsal line, and bent downward on the sides ; without any rostrum. 

 Body many-jointed, 31 segments extending out from beneath the cara- 

 pace ; the last segment broader than the preceding and terminating in 

 two spines." (Bull. U. S. Geol. Survey, No. 30, p. 147.) 



Marshi, Walcott, 1884; Bull. U. S. Geol. Survey, No. 10, p. 50, pi. 10. 



Middle Cambrian. 



Marshi, Walcott, 1886; Bull. U. S. Geol. Survey, No. 30, p. 148, i)l. 15, 

 fig. 1. 

 Pterygotus, Agassiz, 1844; Mon. Poissons Fossiles, etc., note, p. xix. 

 See figure on next page. 



acuticaudatus, Pohlraan, 1882; Bull. Buffalo Soc. Nat. Sci., vol. 4, p. 24, 

 pi. 2, fig. 3. Waterlime. 



Cobbi, Hall, 1859 ; Pal. New York, vol. 3, p. 417*, pi. 83 b, fig. 4, pi. 84, 

 fig. 8 ? Waterlime. 



bilobus (Huxley & Salter), Pohlman, 1886 ; Bull. Buffalo Soc. Nat. Sci., 

 vol. 5, p. 27. Waterlime. 



Bufl'aloensis, Pohlman, 1881 ; Bull. Buffalo Soc. Nat. Sci., vol. 4, p. 17, 

 figs. 1, 2. Waterlime. 



Buffaloensis, Pohlman, 1882; id., vol. 4, p. 44, pi. 3, fig. 3. 



Buffaloensis, Pohlman, 1886; id., vol. 5, p. 24, pi. 3, fig. 1. 



Cummingsi, Grote & Pitt, 1875; Bull. Buffalo Soc. Nat. Sci., vol. 3, p. 18, 

 figure. Waterlime. 



Cummingsi, Grote & Pitt, 1878; Proc. Am. Assoc. Adv. Sci., 26th Meet- 

 ing, p. 300, figure. 



globicaudatus, Pohlman, 1882; Bull. Buffalo Soc. Nat. Sci., vol. 4, p. 42, 

 pi. 2, fig. 2. Waterlime. 



macrophthalmus, Hall, 1859; Pal. New York, vol. 3, p. 418*, pi. 80 a, 

 figs. 8, 8 a. Waterlime. 



macrophthalmus, Pohlman, 1882 ; Bull. Buffalo Soc. Nat. Sci., vol. 4, p. 44. 



Osborui, Hall, 1859 ; Pal. New York, vol. 3, p. 419*, pi. 80 a, fig. 9. 



Waterlime. 



quadraticaudatus, Pohlman, 1882; Bull. Buffalo Soc. Nat. Sci., vol. 4, 

 p. 43, pi. 3, fig. 1. Waterlime. 



