CLASSIFICATION. 37 



in his memoir on tin- I'ala'ozoic Asteriadae figured as Uran/cr, some or wliich arc now- 

 grouped in the genus Fa/ar/'^/c/-. 



M. (ioldfuss^ has figured as Aslerias obtusus, a remarkable astcriad whicli was 

 obtained bv Alberti from tlic Muschelkalk of Friedrichshall in AViirtembers:. 



It has been long known to palaeontologists that a remarkable ehangc is observed in 

 the generic characters of many fossil animals found in the secondary formations when 

 compared w^ith those belonging to the same classes which are entombed in the Pakeozoic 

 series. Reptiles, fishes, mollusca, and articulata afford abundant evidence of such change' 

 and the sub-kingdom radiata supplies additional proofs of the same organic law. 



As the Oolitic Asteriadaj will be figured and described in detail in this monograph, it 

 is only necessary to state here that nearly all the species belong to the genera Urmter, 

 A.slroj/ccfm, LukVui, Plu Piaster, and Goniaxfcr. The fossil species all appertain to extinct 

 forms, but the genera to whicli they belong are nearly all living in our present seas. 



The Cretaceous Asteriadye, which have already been beautifidly figured in Dixon's 

 ' Geology of Sussex,' will form the subject of a future monograph, to succeed the Cretaceous 

 Echinidac now in course of publication. These interesting star-fishes of the Chalk period 

 range themselves for the most part in the genera Orcdsfi'i; Goniotdscifs, AHiroyoniuut, 

 S/c//a>^/er, and Arfhraxfcr. 



The Tertiary formations have hitherto yielded very few species of Asteriad.e. Those 

 from the English tertiaries, representing Asfropecten and Goninsfer, have been figured by 

 Professor Edward Forbes," in his Radiaria of the London Clay ; and the specimens from 

 the Vienna basin, likewise belonging to the geneva Asfrojjecfeti and Gonia-sfer, have been 

 figured and described by Dr. Camil TIeller in his paper " uber neue fossile Stelliriden."" 



CLASSIFICATION OF THE ASTERIADiE. 



The numerous forms presented by the animals of this division early induced Llhwyd 

 and Petiver to give generic names, as Asferisci/s and Echinai^fer, to certain of the group. 

 The first systematic monograph Avhich appeared was published by J. H. Linck' of 

 Leipsic ; this work was illustrated by forty-two well-executed plates, representing the 

 leading forms known to him. This author divided the Star-fishes {Axfcrias, Jjinn.) into 

 two sections, I. Stellis eissis. — II. Stellis integris, characterised by the presence or 

 absence of ambulacra on the underside of the rays. In the first section, which 



i Goldfuss, 'Petrefacta Germanise,' Band i, p. 208, t. G3, fig. 3- 



- PalaeontographicHl Society Volume for 1852. 



3 ' Akademie der Wissenscliaften,' Band xxviii des Jahrgungcs 18.38, Wien. 



'' 'Dc Stellis Marinis liber singular!.*. Tabularum aenearum figuras,' Lepsic, \.7'-i'-^- 



