STUDY OF THE GRAPTOLITES. 229 



described and figured a species under the name Orthocei'atites serratus 

 [Petrefaktenkunde, p. 56, pi. viii, iig. 3.) 



1828. Ad. Rrongniart described two species of graptolites from the 

 Transition formation at " Pointe Levi pros Quebec dany le Canada," as 

 Fucoides dentatus and F. serra^^ {Histoire des Vcgctaux Fossiles, pp. 70 

 and 71, pi. vi, fig. 7-12). 



1829 [1831?J. F. HoLL republished the description of Orthoceratites 

 serratus of Schlotheim {Handbuch die Peti-efact., Vol. ii, p. 234). 



18 — ? Prof. NiLSSON recognized the graptolites as polyps belonging 

 to the ceratophydians. He proposed to substitute the pre-occupied name 

 of Priodon for that of Graptolithus (See Dr. Beck, in Murchison^s 

 Silurian System, p. 696). 



1835. Prof. Bronn, adopting the opinion of Prof. NiLSSON regarding 

 the nature of graptolites, gave the name Lomatoceras {Lethea Geognostica, 

 Vol. i, p. 55, pi. i, fig. 13, L. j^riodon), at the same time arranging the 

 species with the orthoceratites, etc. 



1837. HisiNGER described five species of graptolites from the rocks 

 of Sweden, adopting the generic name Preo7zo^?^5, proposed by Prof. Nilsson. 

 Among these are two species of Linn^us, P. Sagittarius and P. scalaris; 

 to which he added the new species P. pristis, P. folium, and P. convolutus 

 {Leth. Suecica, p. 113, pi. 35). In the second supplement to that work, 

 published in 1840, two other species are added, under the names P. gemi- 

 nus and P. teretiusculus ; the latter being of the type of G. scalaris 

 (Supp. ii, p. 5, pi. 38). 



1839. Sir Roderick Murchison described and figured in the Silurian 

 System three species of graptolites, G. ludensis, G. murchisoni, and 

 G.foliaceus [Sil. System, p. 695). 



1840. Prof. EiCHWALD published a description of Lomatoceras distichus, 

 a graptolite from the Silurian formation of Esthonia {Sil. Syst. in 

 Esthland, p. 101). 



1840. Prof. Quenstedt sought to re-establish the opinion that the 

 graptolites are true orthoceratites {N. Jahrb. f. Min., 275). 



1842. Prof. Geinitz described and figured five species of graptolites 

 under the names G. foliaceus, Murchison, G. priodon, Bronn, G. luden- 

 sis, Murchison, G. serratus, Schlotheim, G. scalaris, Linn^us, and 

 G. spiralis, Geinitz ; regarding them as belonging to the Cephalopoda 

 {N. Jahrb. f. Miri., p. 697). 



1842. Vanuxem identified a graptolite of the Utica slate with the 

 Fucoides dentatus of Brongniart. Graptolithus dentatus, Vanuxem ; 

 G. pristis. Hall, Hisinger? {Geol. Rep. M Dist. N. Y., p. 57, fig. 2). 



1843. Gen. Portlock, in his Geological Report, discussed the nature 

 of the graptolites, recognizing them as true zoophytes, and indicating 

 their analogy with Sertularia and Plumularia. He suggested that the 



* These species are probably identical with those which I have heretofore described as 

 G. pristiniformis and G. hryotioidea. 



