70 FOSSIL ASTEROIDBA. 



small closely-fitting plates. In the radial areas these plates are polygonal and are 

 about 1*8 mm. in diameter. In the interradial areas the plates measure only 1 mm. 

 in diameter and are rhomboidal. All the plates are covered with a fine uniform 

 granulation (PI. XVIII, fig. 2 a). Upon very many of the plates are valvate 

 pedicellarige. Post-mortem changes have produced a sinking in of the plates over 

 the interradial areas. Depressions, doubtless due to similar causes, appear in 

 recent forms when dried, as also in G. elegans. I have been unable to distinguish 

 either the madreporite or the anus. 



The arms are not so much produced as in G. elegans. 



R : r : : 62 mm. : 29 mm. in the specimen at Northampton. 



R : r : : 55'6 mm. : 25'8 mm. in the British Museum (Natural History) 



specimen. 



The width of the arms at the sixth supero-marginal (reckoning from the inter- 

 radius) is 11 '5 mm. 



The supero-marginalia are oblong in shape. In the interradial areas they are of 

 fairly constant size, measuring 5'2 mm. in breadth and 2mm. in length. They 

 diminish in size distalwards. They are eighteen in number, and often bear one 

 or more valvate pedicellarige. The margin is rounded and is about 8 mm. high. 



The infero-marginalia are equal in number and similar in appearance to the 

 superior series. 



The actinal interradial areas are large and filled proximally with a number of 

 small rhomboidal plates about 1'2 mm. in average breadth. The more distal 

 plates are croAvded, smaller, and polygonal in appearance. Traces of a fine 

 granulation are visible. 



The adambulacrals are a series of small oblong prominent plates. The largest 

 are about l'6mm. in length and 1 P 2 mm. in breadth. Remains of their armature 

 are still present. The mouth-angle plates are small and but slightly prominent. 

 They also bear traces of armature. Valvate pedicellariae are scattered apparently 

 irregularly over all these various plates. 



Locality and Straf {graphical Position. Upper Greensand of Blackdown. 



Remarks. Forbes considered this species was equivalent to Asterias Schultzii, 

 Roemer. 1 In this latter species, however, the superomarginalia meet across the 

 dorsal surface of the ray, which would disprove Forbes' statement. 



1 Eoemer, ' Versteinerungen des Norddeutschen Kreidegebirges,' pi. vi, fig. 21. 



