252 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 



imal portions concave; the distal portions of the plates bending upwards; 

 the faces supporting the interradials broadly truncated. Eadials sometimes 

 smaller than basals and interradials, their lower faces decidedly angular. 

 Costals smaller than the radials ; the second shorter and narrower than the 

 first. Distichals to the height of the second plate incorporated into the 

 calyx, the succeeding ones free ; the plates short and semilunate. Eegular 

 interradials : 1, 2, 3, the first nearly as large as the basals, the upper ones 

 considerably smaller ; the supplementary pieces irregularly distributed among 

 the interrays, or absent altogether. Tegmen as in the preceding species. 



Horizon and Locality, — Same as last. 



Type in the National Museum at Washington. 



RemarJis, This form was described by White in 1880 under the name 

 of Rhodocrinus vesperalis, and it was stated that the specimen probably came 

 from the coal measures, thirty miles west of Humboldt, Kans. S. A. Miller 

 redescribed the species in 1882 as Lyriocrinus sculptus,^ giving " Tennessee " 

 as locality, and '' Niagara group " as the probable horizon. The specimens 

 from which our figures are made were collected by one of us in 1883, from 

 rocks of the Trenton group at Knoxville, Tenn., where they were found 

 associated with Hylocrinus and other typical Trenton forms. We have com- 

 pared these specimens carefully with White's type of Rhodocrinus vesperalis in 

 the National Museum, and also with Miller's Lyriocrinus sculptus in his own 

 collection, and not only find the various specimens specifically identical, but 

 think it most probable that they all came from the same locality. 



Diabolocrinus Meroglyphicus W. and Sp. (nov. spec). 



Plate X. Figs. Sa, h, c. 



Calyx globose ; basal portions deeply depressed, forming a narrow fun- 

 nel-shaped pit, of slightly pentangular outline, which encloses the whole of 

 the infrabasals and one fourth of the basals. Arm openings directed ob- 

 liquely upwards, and invisible in a dorsal view. Plates of the dorsal cup 

 covered with numerous elongate nodes, of irregular form, which give to 

 the surface an appearance suggestive of being densely covered with hiero- 

 glyphics. The rays are marked by conspicuous ridges following the median 

 line of the plates, and similar ridges pass out from the centre of the radials 



* It was described in the Journal of tlie Cincinnati Society under the name of Lyriocrinus sculptilis ; 

 but Miller, on finding the name preoccupied, changed it in his private edition to L. 



/ 



