70 FOSSIL ASTEROIDEA. 



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 

 pedicellarifB. 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 C. elegans. I have been unable to distinguish 

 either the madreporite or the anus. 



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



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

 E. : r : : 55*6 mm. : 2.5'8 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 thej- are of 

 fairly constant size, measuring o*2 mm. in breadth and 2 mm. in length. They 

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

 or more valvate pedicellarite. 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 proxinially with a number of 

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

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

 granulation are visiljle. 



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

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

 are still present. The mouth-angle plates are small and but slightly j^rominent. 

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

 irregularly over all these various plates. 



Locality nud Straiigraphical Position. — Upper Greensand of Blackdown. 



Remarks. — Forbes considered this species was equivalent to Asterias Schiiltzii, 

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

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



^ Eoemer, ' Versteiaerungen des Norddeutsclien Kreidegebirges,' pi. vi, fig. 21. 



