10 HISTORY OF THE CRINOIDE^ 



much resembles the large West Indian Pentacrinns, that it was for 

 several years thought to be a distinct species of that genus, and was 

 in consequence called Pentacrinus Eurojxcus. When further advanced 

 the head, having assumed the form of a Comatxda, separates from 

 the stalk, and during the remainder of its life moves about through 

 the ocean. As the highly important paper in which this wonderful 

 fact was communicated to the world ought to be in the hands of 

 every student of geology, and as also it is difficult to procure, I have 

 published it entire, wnth copies of all the original figures, at the end 

 of this Decade. 



The next publication in which any great advance in the knowledge 

 of the anatomy of the Crinoideae was made appeared, in J 841, in the 

 " Transactions of the Royal Academy of Sciences of Berlin." It was 

 a paper entitled, '' On the Structure of Pentacrinus caput-McdustB,^^* 

 containing the observations made by the late Professor J. Miiller 

 while dissecting a specimen which had been captured in the West 

 Indian seas and preserved in spirits. In this memoir Prof. Miiller 

 shewed that the grooves which extend from the mouth along the 

 ventral surface to the bases of the arms, and are thence continued 

 upon the arms to their extremities, are true ambulacra, closely allied 

 to those of the Star-fishes. He also greatly improved the nomen- 

 clature of the different portions of the skeleton. 



In 1854 MM. L. DeKoninck and H. LeHon issued an admirable 

 work, entitled " Researches on the Crinoids of the Carboniferous 

 Formation of Belgium,"! in which these excellent paleeontologists 

 give a most able review of the whole subject of the skeleton and 

 classification of these fossils. They have improved the nomen- 

 clature, until it is now nearly perfect; and they also devised an 

 ingenious formula, by the use of which all the leading characters of 

 a genus can be expressed by a few words and figures. I shall make 

 an application of this formula to all the Canadian genera. The 

 work besides includes a catalogue giving the title, date of publication 

 and author's name of every book or pamphlet known to contain any 

 description or allusion to the Crinoids from the time of Agricola, in 

 1558, up to the year 1854. There are upwards of three hundred 



• Uber den Bau des Pentacrinus caput-MeduscB. (^Abhandlungen der Koniglichen 

 Academic der Wisenschafften zu Berlin, 1841, page 177.) 



t Recherches sur les Crinoides du Terrain Carbonifere de la Belgique. Par L. 

 DeKoninck et H. LeHon, suivies d'une notice sur le genere Woodocrinus. BruxelleSj 

 1854. 



