18 THE CEINOIDEA CAMERATA OF NOETH AMEEICA. 



the latter family, to whicli he applied the name " Pycnocrinidees/' is divided 

 into four Tribus, — the " Eugeniacriniens, Encriniens, Apiocriniens, and Pen- 

 tacriniens." His second and third families comprise " Blastoides " and " Cys- 

 tidees ; " the remaining ones, the ^' Tessellata" of Miiller. 



It is somewhat carious that Pictet, while placing Cupi^essocriniis, Eiica- 

 li/piocriniis, and Crotalocrinus each in a separate family, referred all the 

 other Palaeozoic Crinoids to only two families, — the " Haplocrinides" and 

 '' Cyathocrinides." His Haplocrinides embrace Haplocrinus, Coccocriniis, Cera- 

 mocnmis, Myrtilocrinus, Epaetocrinus, and Gasterocoma ; all the other Palaeocri- 

 noidea were placed under the Cyathocrinides. It is difficult to understand 

 upon what ground Pictet's families were based. His " Polycrinides," with 

 Eucalypiocriniis^ have closer affinities with Melocrinus and Dolatocrimis than 

 these with Cyathocrinus ; while Cupressocrmis agrees closer with the Haplo- 

 crinides than many of the Cyathocrinides among themselves. 



Pictet subdivided the Cyathocriniens into four tribus, — the " Cyatho- 

 criniens," the " Actinocriniens," the " Carpocriniens," and the " Platycri- 

 niens," — of which the first are dicyclic, the last monocyclic ; while the 

 Actinocriniens and Carpocriniens are in part monocyclic and in part dicyclic. 

 He did not discriminate between genera in which the lower brachials form 

 part of the calyx and those in which they are free, nor did he pay the least 

 attention to the presence or absence of anal plates. 



The classification of Pictet, although not so satisfactory as that of Roemer, 

 was accepted by Dujardin and Hupe.* The latter, however, changed the 

 sequence of the families, making the '' Cystidees " the first family, and 

 placing the " Comatulides " last. 



In America, up to 1858, little attention had been paid to the study of 

 Crinoids. Of the fourteen hundred American species that are now described, 

 only about seventy were then defined. In 1843 and 1851, Hall had de- 

 scribed a moderate number from the Silurian in the Palaeontology of New 

 York, Yols. I. and II., and a few additional ones through the Regent's 

 Reports at Albany, Owen and Shumard, in 1852, United States Geological 

 Report of Wisconsin, Iowa, and Minnesota, described nineteen species from 

 the Subcarboniferous of the Mississippi Yalley, mostly from the Burlington 

 group; and Shumard, in Swallow's Missouri Geological Report of 1855, 

 twelve species from the same horizon. The few remaining species had been 

 described by Conrad, Roemer, Casseday, and Yandell and Shumard. 



* Histoire Naturelle des Zoophytes Echinodermes, par M. F. Dujardin et M. H, Hupe, Paris, 1862. 



