136 BULLETIN" 88, UNITED STATES NATIONAL MUSEUM. 



NEOPAL^EASTER CRAWFORD SVILLENSIS (Miller). 



Plate 13, fig. 5; plate 23, fig. 4. 



Palseaster crawfordsmllensis MILLER, Journ. Cincinnati Soc. Nat. Hist., vol. 2, 

 1880, p. 256, pi. 15, fig. 3; N. Amer. Geol. Pal., 1889, p. 265, fig. 379. 



Original description. "This species is founded upon the dorsal 

 view of a single specimen. The rays are longer than the diameter of 

 the body, and not of uniform size. They are flattened or depressed 

 in the middle, as is also the central part of the body. Many of the 

 plates possess a central tubercle or small spine, and probably all of 

 them did. 



"The marginal plates are large ; somewhat elliptical in outline, and 

 have their shorter diameters in the direction of the length of the 

 rays. There are about 12 plates on each side of a ray, and they 

 come together at about the eighth plate from the body, though in 

 the ray opposite the madreporiform tubercle they come together at 

 the seventh. The space between the marginal plates of each ray 

 is filled with smaller plates; three of these unite the larger plates at 

 the body, but they diminish in number toward the apex of the ray, 

 and cease at the eighth plate. In addition to the two large plates 

 which form the junction of the rays with the body, a few large plates 

 cover the outer part while the central part is covered by smaller 

 plates. The madreporiform tubercle is supported by three plates, 

 two of them are large marginal plates, which form a junction between 

 two rays, and the other is a large plate within, forming part of the 

 covering of the body." 



Emended description. The type-specimen measures: R, = 22 mm., 

 r=7 mm., K, = 3.1r > . Width of rays at base 7 mm. Another speci- 

 men in the Museum of Comparative Zoology has rays 3 mm. longer. 



Rays short, tapering rapidly. Disk rather large for a small species. 



Abactinally the disk has a central circular plate surrounded by 

 numerous small, conical, irregularly disposed, accessory plates, among 

 which are a few larger pieces usually adjacent to the large interradial 

 plates. Outside of the small disk plates is a ring of very large, irregu- 

 larly shaped, radial and interradial plates. Five of these are inter- 

 radial in position, and are situated just within the basal plates of 

 adjoining supramarginal columns. These plates may remain normal 

 as a single plate or may be divided into two plates, when they some- 

 what resemble inwardly crowded supramarginals. Upon these 

 laterally and distally rest five large radial pieces, the basal plates 

 of the radial columns. It is very probable that the radial columns 

 are continuous from the basal plate to near the distal portion of the 

 ray, where a few of these plates are much reduced in size and are 



