INTRODUCTION 



1 References' 



1724 Bromell, M. v. Lithographia Suecanae. Specimen prim, et secund. Acta lit. 



Sueciae Upsaliae public, v. 1 and 2 (1720-29) 

 1735 Linne, C. v. Sjstema naturae, ed. 1. Regnum lapideum. Classis 3, Fossilia, 



Ordo. 3 



1821 Wahlenberg, G. Petrificata Telluris Suecanae. Nova Acta Reg. Soc. Scien- 



tiarum Upsal, 8 : 92 



1822 Schlotheim, E. F. v. Petrefaktenkunde, p. 56 

 1828 Brongniart, A. Histoire des Vegetaux Fossiles, p. 70 



Nilsson. See Dr Beck in Murchison. Silurian System, p. 696 

 1837 Hisinger, W. Lethaea Suecica, seu Petrificata Sueciae. Supplementum 



1839 Murchison, R. J. Silurian System, pt 2, p. 695 



1840 Quenstedt, F. A. Ueber die vorziiglicbsten Kennzeichen der Nautileen. Neues 



Jalirb. fiir Mineral, p. 253 

 1842 Geinitz, H. B. Neues Jabrbuch fiir Mineral ogie, p. 697 



1842 Vanuxem, L. Geology of New York, Report on Tbird District 



1843 Portlock, J. E. Geological Report on Londonderry, Tyrone and Fermanagh 

 1843 Mather, W. W. Geology of New York. Report on First District 



1843 Emmons, E. Geology of New York. Report on Second District 

 1843 Hall, J, Geology of New York. Report on Fourth Geological District 



1846 Geinitz, H. B. Grundriss der Versteinerungskunde, p. 310 



1847 Hall, J. Palaeontology of New York, v.l 



1848 Sedgwick, A. On tbe Organic Remains found in the Skiddaw Slates, etc. Quar. 



Jour. Geol. Soc. 4 : 216 

 1850 Barrande, J. Graptolites de Bobeme extraits du systcme silurien du centre de la 

 Bobeme 



1 For lists of graptolite literature, see Perner, J. £tiides sur les Graptolites de Bohgme, 3 i^me 

 partie, p. 3; Wiman, C. Ueber die Graptoliten, p. 2; Roemer & Freeh. Lethaea pala«ozoica, 

 1 : 544 ; EUes & Wood. Monograph of British Graptolites. The list here given does not contain the 

 greater portion of the literature on Upper Siluric forms. 



