204 REPORT ON THE STATE CABINET. 



This appearance we now know to be due to the direction of the pressure 

 upon the body exerted at right angles to the cellules, and which will be 

 explained in the sequel. 



The earliest opinion regarding these fossils was that they were of vege- 

 table origin;* and they have been thus considered by some authors even 

 at a very late period. Brongniart, in his great wox'k, Histoire des Vegetaux 

 Fossiks, has figured two species among the AlgjB. This reference was 

 followed in the earlier part of the Geological Survey of New York, by 

 Conrad, Mather, Vanuxem and Emmons. The animal nature of the 

 Graptolite was first recognized by Walch, who figured two species which 

 he describes as small toothed Orthoceratites. His view was subsequently 

 maintained by Wahlenberg, and after him by Schlotheim, who referred 

 them to the Cephalopoda, regarding them as extremely slender Orthoce- 

 ratites. This opinion may have received support from specimens in 

 such condition as G. scalaris, where the indentations are limited on each 

 side by a continuous margin ; but in such as present a single or double 

 series of marginal serratures, the analogy seems very remote. Professors 

 Geinitz and Quenstedt advocated the same view at a much later date ; 

 though it has since been abandoned by these authors, from more extended 

 investigations. Bceck supposes the Graptolites may have been the arms 

 of Radiata or Cephalopoda. 



Professor Nilsson first suggested the true relations of these fossils, and 

 maintained that Graptolites were Polyparia, belonging to the Family 

 Ceratophyta. Dr. Beck, of Copenhagen, regarded them as belonging to 

 the Group Pennatulidae, of which the Linnean Virgulmia is the most 

 nearly allied existing form. Sir Boderick Murchison has adopted this 

 ' view of the relations of the Graptolites in his Silurian System.'] General 

 PoRTLOCK has fully recognized the Graptolites as Zoophytes, and has 

 pointed out their analogy with Sevtularia and Plumiilana. 



The relations of Graptolites with the Cephalopoda had already been 

 fully disproved by M. Barrande (in the first chapter of his ^'■Graptolites 

 de Boheme"), before the abundant materials for the refutation were 

 discovered in the remarkable forms of the Quebec group ; and most 

 naturalists were already agreed in referrmg these bodies to the Class 

 Polypi, to which they doubtless belong. 



*• Bromel Qjicta Upmla, p. 312, 1727), referred the Graptolites of Sweden to the fossil leaves 

 of grasses. 



t Silurian System, page 694; and letter of Dr. Beck, pp. 695-6. 



