44 THE CANADIAN NATURALIST. [Feb. 



Professor Nilsson first suggested that graptolites were Polypiaria, 

 belonging to the family Ceratophyta. Dr. Beck, of Copenhagen, 

 regarded them as belonging to the group Pennatulidse, of which 

 the Linnean Virgularia is the most nearly allied existing form. 

 Sir Roderick 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 Sertularia and Plumularia. 



The relations of graptolites with the Cephalopoda had already 

 been fully disproved by M. Barrande (in the first chapter of his 

 Graptolites de JBoheme), before the abundant materials for the 

 refutation were discovered in the graptolites of the Quebec group ; 

 and most naturalists were already agreed in referring these bodies 

 to the class of Polypi, to which they doubtless belong. 



More recently, Mr. McCrady, of South Carolina, has published 

 a paper on the " Zoological Affinities of Graptolites/'f in which 

 he has endeavored to show the similarity of the graptolitic forms 

 with the Echinoderm larvae, as illustrated by M tiller. There is 

 certainly much resemblance between the enlarged figures of that 

 author, and some forms of graptolites in the shales of the Hud- 

 son River valley ; while some of the figures with central discs 

 have a more remote analogy with certain forms from the Quebec 

 group. Some of the toothed rods of the Echinoderm larvae likewise 

 bear a resemblance to the graptolites figured by Mr. Suess ;J and 

 there are still further analogies pointed out by Mr. McCrady, 

 which, however, may not be regarded as of equal value by the 

 greater number of naturalists. 



For my own part, although admitting the similarity of form and 

 of some of the characteristics which were very kindly pointed out 

 to me by Mr. McCrady, long before his publication, I cannot 

 recognize the analogy sought to be demonstrated. The establish- 

 ment of the fact that these toothlets or serratures are the exten- 

 sions of true cellules, each one having an independent aperture, 



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



f " Remarks on the Zoological Affinities of the Graptolites, by John 

 McCrady, made before the Eliot Society of Natural History of Charles- 

 ton, S. C, at the meeting of July 15, 1857. " [Extract from the Pro- 

 ceedings, vol. i.] 



t Naturwissenschaftliche Abhandlungen. Vierter Band. Tab. viii 

 and ix. 



