Prof. Agassiz on the Echinodermata. 299 



for 1840; M. Steininger that oi Halocrinites, in the eighth 

 and ninth volumes of the Bulletin of the Geological Society 

 of France, and in the first volume of the Transactions of this 

 Society. MM. Quenstedt (Wiegm. Archiv, 1835) and Bronn 

 (Jahrb. fiir Min. 1837) have described some new species of 

 Encrinus from the muschelkalk ; so that three species of this 

 remarkable genus are now known. 



Mr. Phillips, in the second part of his ' Geology of York- 

 shire/ besides describing many new species belonging to known 

 genera, has established two new genera of Crmoidece from the 

 coal-measures, to which he gives the names Euryocrimis and 

 Gilbertsocrinus. The same writer has moreover described a 

 great number of new Crinoidece belonging to the most ancient 

 fossiliferous deposits, in the work of Mr. Murchison upon the 

 Silurian system, among which we likewise find many new- 

 genera, which he calls Marsiipiocrinites, Hypanthoannites, and 

 Dimerocrinites. The genus Ischadites of M. Konig (Murch. 

 Sil. Sys., pi. 26, fig. 11) also belongs to the Crinoidece ; M. de 

 Buch considers it to be identical with Sphceronites aurant'mm. 

 Under the name Scyphocrinites, M. Zenker has described a 

 peculiar form in this class, in his ' Naturgeschichte der Urwelt.' 

 Lastly, M. de Hagenow has made known a new genus allied 

 to Solanocrinus, which he names Hertha, and many new spe- 

 cies of Crinoidece and Echinidce. 



I shall allude again to the genera Glenotremites of Goldfuss 

 and Ganymeda of Gray, because I have ascertained with cer- 

 tainty that they have been established upon crinoidal axes 

 belonging to the family of the Comatulce, and consequently 

 they ought to be suppressed. As regards the genera Ca- 

 ryocrinites, Say, and Trianisites, Rafinesque, these are only 

 known to me by name. The genus Marsupjites of Mr. Mantell 

 [Marsupium, Koni2;) is too well known to be mentioned as a 

 recent acquisition to the science of palaeontology. 



M. Romer, in his work upon the Jurassic fossils of the north 

 of Germany, and in his second work upon the cretaceous fos- 

 sils of the same country, describes a considerable number of 

 new species amongst the Echinites and Crinoidcd'. MM. Koch 

 and Duuker have described many new Echinites in the Sup- 

 plement to the first work, and M. Hinsinger those of the for- 

 mations in Sweden in his * Lethsea Suecica,' accompanied with 

 excellent figm'es. 



The family of the Crinoidece ought especially to engage the 

 attention of naturalists, inasmuch as, from the great variety of 

 forms which it contains, it will furnish the clue to the deve- 

 lopment of the entire class Echinodermata. These forms are 



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