IV 



recognize the Niagara beds in the middle Pennsylvania. — The two small 

 figures (6) represent shagreen scales of Thelodus parvidens, Ag. The four 

 figures (c) were formerly Piectrodus mirabiliSy Ag. but are now known as 

 Sukeraspispustuliferay Ag. (allied to Cephalaspis. ) (Olaypole.) 



502, 11. Read L. C. (Matthew)— O. excentrica, O. parmulata, and the 

 two lower figures of Rogers and Emmons are all four Discina. ( Whitfield) . 

 See note 481, 7, above. The figure from Rogers ''looks like the basal epi- 

 theca of some species of Monticulipora.^^ (Jos. F. James.) 



503, 13. Read Oryctoblattlna, and transfer to p. 569 below. (Scudder.) 

 506, 27. Read gaudryi. (Olaypole.) 



509, 5, Read biforata. 



510, 22. In Band c of Division 1. (Matthew.) — 30. Insert Dalman. 

 (Olaypole.) 



513, 1. Probably Strephodonta demissa. (Whitfield.) —30. No con- 

 nection whatever with O. michelini. (G. K. Greene.) 



519, 10, 11. Erase 57-35, and 64-4. — 35, 36. This specimen should be re- 

 exami ned. ( Olaypole. ) 



521,1. Streptorhynchus umbraculum, (Oollett.) — 24. O. lenticularis. 

 Name preoccupied by Dalman for a Oambrian species. (Matthew.) 



523, 4. Read Delthyris. — 13. Read biforata. 



524, 1. Read michelini. (Same on p. 529, 13.) 



526, 21. Oollett thinks this O. carbonaria. Read pecosl, Marcou. (Olay- 

 pole. ) 



531, 1. For Hall read Meek. — 18. Read Poramtoonites puactostriata' 

 the only American species of this genus known. (R. P. Whitfield.) 



532, 7. Read Hawesville. — 9. Read retrorsa. Same as O. carleyi. 

 (Whitfield.) 



633, 1. O. sinuata=0. occidentalism Hall. (Whitfield.) 



536, 13. " And this one is a Lani^llibranchiate." (Whitfield. 



537, 21. For Perry read Mifflin Co. (Olaypole.) 



538, bottom line. ''Identification of Tully limestone doubtful." (Olay- 

 pole. ) 



541, O. anceps. Figure that of a (^on^oce7'as. (Whitfield.) 



544, 15. Read O. anceps. 



547, 9. Erase IX. " This is not the IX of Rogers. It is Chemung [ VII T </] 

 everywhere in the whole Appalachian basin except in N. E. Pennsyvania 

 (Pike Oo. ) and adjacent part of New York. It carries a distinctly Chemung 

 fauna in Virginia, Maryland, Pennsylvania and New York everywhere 

 except in the little area of a few hundred square miles. I have followed it 

 out everywhere. It is not the IX of Bedford and Fulton." (J. J. Steven- 

 son.) 



550. Figure. "This is only the duter portion of Gyrtoceras eugiiirn^ Hall. 

 (Whitfield.) 



555, 7. Now in the Mus. Oom. Zool. Oambridge, Mass. 



562,6. Erase "or /S'a^ma." (Olaypole.) 



563, 17. Read Orthonoto. 



565, 26. Read Lowest coal measures , just over XII. 



56^, next to bottom line, ^esidi obseletum. (E. W. 0.) 



567,22. Read parallelum. (E. W. O.) 



568, 24. Read conicum. (E. W. 0.) 



569, 17. Insert Dry ctoblattina from p. 503. — 18. Read Ostracods. 

 571,35 ; 572, 2 ; 573, 1. Read 0. H. Hitchcock. 



