PALEONTOLOGIC CONTRIBUTIONS 5 I 



Urasterella sp. no v. 



Plate 13, figures 7 and S 



Professor Schuchert records the presence of a large, slender 

 rayed species in the Ithaca beds of the neighborhood of Ithaca, of 

 which, however, so little actinal detail is preserved that only the 

 presence of the species could be indicated. The State Museum 

 contains another like specimen, collected by the writer in the Ithaca 

 beds at Messengerville, Cortland county, N. Y. Unfortunately this 

 specimen also shows only the abactinal side since the counterpart 

 of the specimen could not be found. The R (radius of ray) of 

 this species was from 45 to 50 mm long. The ray shows in the 

 median line a more or less interrupted row of somewhat elongate 

 small ossicles, the radial plates; on either side of this, larger rhombic 

 plates are seen ; outside of these two rows of large rhombic plates 

 and along the edge smaller disk-shaped plates with rods. All the 

 radial, supramarginal and ambital plates are spinose or bore rods 

 after the fashion of the other species of Urasterella. In one place 

 along the edge the impressions of long, slender, flattened and longi- 

 tudinally grooved spines can be observed protruding from the 

 actinal side. These have been described by Schuchert from U . 

 grandis (Meek) and considered as probable paxillae attached 

 to the articulate spines of the adambulacrals. 



The little that is known of this species leaves no doubt that it is 

 quite different from the U . s t e 1 1 a of the Naples beds, both in 

 relative size and the character of the ossicles of the abactinal region 

 of the rays. 



Palaeosolaster roemeri (Clarke) 1 



This species, proposed by Doctor Clarke in New York State 

 Museum Bulletin 121, page 64, plate 11, is based on a magnificently 

 preserved specimen from the Bundenbach slate of the Rhenish 

 Devonian. The genus is represented by only one other species, P . 

 g r e g o r y i Stiirtz, also existent in but one specimen. 



The species had originally been referred to Helianthaster which 

 is distinguished from Palaeosolaster mainly in the number of the 

 rays ; and its differences from the supposed congeners were pointed 

 out. In general aspect P. roemeri is so similar, though much 

 larger, to the genotype as to suggest identity; we therefore desire 

 here to point out the specific differences between the two. 



The proportions between the free parts of the rays and the disk, 

 as well as the relative width and length of the rays and the mouth, 



1 By John M. Clarke. 



