FOSSIL ASTEROIDEA. 



DESCRIPTION OF THE CRETACEOUS SPECIES. 



S«i-c?ass— EUASTEROIDEA, Sladen, 1886. 



Or(ie?-— PHANEROZONIA, Sladen, 1886. 



FiTwtVy— PENTAGONASTERID^, Perrier, 1884. 



Phanerozonate Asterids, with thick and massive marginal plates, which may 

 be either naked, or bear granules or spiniform papillae. Disk largely developed. 

 Apical plates often increscent. Abactinal surface tessellate, with rounded, poly- 

 gonal or stellate plates, which may be tabulate or paxilliform. Actinal inter- 

 radial areas largely developed, covered with pavement-like plates, which may be 

 naked or covered with membrane, or may bear granules or spinelets. 



The family Pentagonasteridae, as defined by Prof. Edmond Perrier' in 1884, 

 was separated from a larger and more comprehensive group of genera which had 

 been previously recognised by him* as constituting the family Gouiasteridas. The 

 name Goniasteridae was not retained for any of the groups or families into which 

 that incongruous series of genera was divided. Previous to 1875, even the generic 

 name of Goniaster had been very loosely and incorrectly applied. The vaguest 

 notions as to the limits or characters of the genus seem to have been held. The 

 mere form of the body, and the applicability of the significant name, irrespective 

 of structural details, appear to have alone determined the reference of a large 

 number of the species which have at different times borne the generic name of 

 Ooniaster. 



1 ' Nouv. Archives Mub. Hist. Nat.,' 2e s^rie, 1884, t. vi, p. ICi. 



' 'E^vis. Stell. Mub.,' p. 25 ('Archives de Zool. exper.,' 1875, t. iv, p. 289). 



