REVISION OF PALEOZOIC STELLEROIDEA. 183 



evident from a view of the plates which remain that they are here 

 larger and more convex than those of the rays. 



" Diameter of the body, five lines. Length of each ray, If inches. 

 Width of the rays at their junction with the body, 3 lines. Depth 

 of the rays from the dorsal to the ventral side of the body apparently 

 somewhat less than the width. The total breadth of the specimen, 

 if the rays were straightened out, would thus be about 4J inches. 



"From the manner in which the rays are curved, it is evident that 

 they possessed a considerable amount of flexibility. The specimen 

 is somewhat distorted by pressure, but a small portion of one of the 

 rays near the body seems to retain its natural shape, and it is here 

 obtusely angulated along the median line. The transverse section 

 of the ray should be, therefore, subpentagonal. There is still, how- 

 ever, some doubt on this point. The under side is unknown. " In 

 places where the specimen is broken the adambulacrals are seen to 

 be as in other species of Urasterella; there appear to be about 60 or 

 more of these plates in each column. 



Locality and 'formation. The only specimen of this species was 

 found by Mr. J. Richardson in strata of Chazy age (bed I of the 

 Newfoundland section) at Point Rich, Newfoundland. The holotype 

 (No. 554) is in the Museum of the Geological Survey of Canada, at 

 Ottawa, which has furnished the photograph illustrating the specimen. 



Remarks. The holotype was seen at Ottawa and the original 

 illustration found to be a fairly accurate reproduction of the charac- 

 ters of the fossil. The abactinal side of the disk has a central disk 

 plate that is large and tumid. Around it is a circle of six smaller, 

 highly convex plates, and at the base of each ray medially there is 

 another single large tumid plate, the basal radial. The abactinal 

 side of the rays is highly convex and somewhat angulated medially. 

 The ossicles are small and distinctly arranged in quincunx, of which 

 there are about six plates in each diagonal row near the base of a ray. 

 In other words, the abactinal characters of U. huxleyi are very much 

 like those of U. ulrichi, with the differences that in the latter species 

 the prominent disk plates are smaller and there are more columns 

 of smaller ossicles on the stouter and longer rays. Further, in U. 

 ulrichi there are two columns of larger abactinal plates along the 

 central area of the rays, while in U. huxleyi all the ray ossicles are 

 of equal size. 



TJ. pulchellus has less convex and more slender rays, and far fewer 

 abactinal plates. 



URASTERELLA ULRICHI, new species. 

 Plate 29, fig. 1; plate 30, figs. 6, 7. 



The smallest specimen measures: R = 14 mm., r = 4 mm., R = 3.5r. 

 The best preserved specimen measures: R = 45 mm., r = 7.5 mm., 

 R = 6/*. The largest specimen measures: R = 78 mm., r=12 mm., 



