812, 9. Read Ambonychia. 



813,40. For 'family " read '*genus.'^ Pterodactylus is a genus of the 

 family of Ornithosaurians, bird-lizards. Prof. O. 0. Marsh describes bones 

 from the Neohrara yellow chalk of Kansas, to which he gave the name 

 (Amer. Jour. Sci. June, 1871). Prof. E. D. Cope in describing similar re- 

 mains from the same Cretaceous deposits along Butte creek, Kansas, re- 

 jects Marsh's name as preoccupied, and describes his own specimens under 

 the names Ornithochirus (Seeley, bird-hand) umbrosus, andO. harpyia : 

 The latter about the size of Marsh's species ; the former "the largest Ptero- 

 dactyle as yet known found on our coCtineet." Cuvier's genus Pterodacty- 

 lus is chiefly known from Jurassic strata. — ( Proc. Amer. Philos. Soc. 

 Philad., p. 420, March 1, 1872). 



818, 1. Compare with Pterinea longispina, (J. F. James,) 



823, last lino. Read " by J. J. Stevenson ; see Claypole," etc. 



824, 1. Read Ichnology^ N. E. — 9. Read Buckland. 



825, 13. Orton makes the Dayton limestone the basal member of the 

 Niagara in Ohio, underlying the Niagara shales. But it is only a local 

 formation. (J. F. James.) 



829,24. Read miniscensis. (E. W. C.) 



830, 4. Read speciosa. (E. W. C). 



831, 24. Read emnierichi. — Next to last line. Head piochensis, (E.W. C.) 



832, 3. Read CrepicephaluSy Owen. — 6, 11. After haguei and iowensis in- 

 sert Hall. — Bottom line. "The St. John group is Middle and not Lower 

 Cambrian.'^ (J. F. James, who would also change Lower to Middle in the 

 cases of P. orestes var. thersites, P. quadrata, P. tener, on pp. 333, 834, 835.) 

 — Line 17. Read misera, (E. W. C.) — Bottom line. Read orestes, 



833, 1. Read Solenopleura rolblbii, var;. thersites. (Matthew.) — 7. Read 

 Liostracus onangondianus. "It differs from Pty chop aria in having no 

 genal spines, &c." (Matthew. June, 1890.) — P. quadrata is the "young 

 of another species, Liostracus onangondianus.'^^ (Matthew.) — P. robbi is 

 a ''^Solenopleura by its inflated cheek, granulated surface, and rounded 

 ends of pleura." (Matthew.) 



833, 4.. Read ther sites. — 26. Read Hall and Whitfield. — 27. Read quad- 

 ratus. (E. W. C.) 



834, 29. Read tenera. (E. W. C.) Read L. teller. (M.) 



835, 15. "If a blind trilobite, it is not a Ptychoparia.^'' (Matthew.) 



835, 17. For Hudson Miver read Utica slate. (E. W. 0.) 



836, 1. Read Oonocephalites. 



837, bottom line. Read Crab Orchard. 



