130 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



in his treatise proved conclusively that the fossil crinoid stems 

 were not independent individuals, as had been erroneously 

 supposed, and gave complete representations of several genera, 

 more especially of the genus Encrinus. 



The first example of a living Pentacrinus came from Mar- 

 tinique, and was described by Guettard, who fully recognised 

 the relationship of the recent species with earlier forms in the 

 Liassic and Jurassic strata. 



Schulze and Parkinson added valuable data to the investi- 

 gation and relationship of sea-lilies, as the crinoids were 

 commonly designated; while Blumenbach classified them in 

 near relationship to the ophiuroids (brittle-stars) and asteroids 

 (star-fishes). But the founder of the more scientific literature 

 of crinoids was Miller of Danzig, who published in 1821 

 his famous work, Natural History of the Crinoidea or lily- 

 shaped Animals. Miller not only gave admirable descriptions 

 of a number of previously unknown species from the Carbon- 

 iferous limestones of Ireland and the Upper Silurian limestones 

 of Dudley, but also proposed a clear terminology for the 

 individual parts of the calyx, the arms, and the stem or 

 column. 



In the case of the important class Echinoidea (Sea-Urchins), 

 contributions to the literature of fossil and existing forms 

 practically kept pace with one another. The first systematic 

 treatment of the Echinoidea was published as early as 1732 by 

 John Philip Breyn of Danzig. In his work all known living 

 and fossil forms were grouped under seven genera. Two years 

 later Klein's Dispositio Echinodermatum appeared, and Leske 

 in 1778 prepared a second and enlarged edition of this impor- 

 tant work. The Klein-Leske classification recognised twenty 

 genera, the names of which have only been partially continued 

 in the literature. The works of Breyn and Klein have both 

 sustained their reputation in zoological and palaeontological 

 literature. 



Fossil molluscs were always awarded a large amount of 

 attention owing to the remarkable number of species, the wide 

 range of distribution and favourable preservation of the shells. 

 Fossil cephalopods were figured in the older works of the 

 seventeenth and eighteenth centuries, as a rule under the 

 names of belemnites, nautilites, ammonites, and orthoceratites. 

 The Gastropods or Snails were sub-divided into numerous 

 genera of somewhat indefinite characters e.g.^ Dentalites, 



