196 NEW YORK STATE MUSEUM 



sisting of a single series of squamous plates overlapping distally 

 along the length of the arm; each of these plates is sharply 

 depressed at the side to form two deep pits corresponding to 

 elevations on the (marginal plates. 



Horizon and locality. Lower Carbonic below the horizon of the 

 Olean conglomerate at Warren Pa. 



Observations. The specimens on which this description is 

 based were collected by Prof. C. E. Beecher and are in the Yale 

 museum. The best of the examples comprises internal and 

 external casts of the body, the parts about the oral aperture 

 being defaced. This specimen is specially interesting in afford- 

 ing evidence of the subambulacral plates. So far as known 'but 

 two instances have passed on record of specimens in which the 

 structure of theise plates is shown, one a specimen of A. c i n - 

 cinnatiensis described by Meek, and the other the original 

 specimen of Roemer's genus Haplocystites from the lower 

 Devonic of the Rhine. Both of these instances are cited by 

 Jaekel, who has given a new illustration of Haplocystites 

 r h e n a n a . It does not however appear f Pom x either of the 

 instances cited that the pavement plates actually overlap each 

 other as shown by this specimen of A. beecheri. 



In size and many of its structural features A. beecheri is 

 similar to A. lebouri Sladen from the lower Coal Measures 

 of Waterhead, Cumberland (see for corrected figures Jaekel, 

 Stammmgeschichte der Pelmatozoen, pi. 1, fig. 7). 



Agelacrinites buttsi sp. nov. 

 PL 10, fig. 7-9 



Disks small, cemented by the aboral surface. Oral surface 

 convex medially, with very broad and flat marginal rim, sharply 

 elevated on its inner edge and composed of minute imbricating 

 plates. Rays five, four of which are solar, R 5 being contrasolar 

 and facing R 1. These are narrow, extend to the edge of the 

 border, their extremities curving close within this edge. Inter- 

 radii composed of imbricating plates. Anal pyramid small and 



