206 Twenty-fourth Report on the State Museum. 



Genus — GLYPTOCKINUS^ Ball 



Glyptocrinus I^ealli n. sp. 

 Plate 5, figs. 18, 19. 

 Calyx turbinate, gradually spreading from the base to the free 

 arms ; deeply pentalobate below the third radial plates, from the 

 depression of the interradial area ; ten-lobed above from the depres- 

 sion of the intersupraradial areas. 



Basal plates very small, presenting a low triangular face on the 



exterior, with very slightly truncated lateral angles. Subradial plates 



larger, heptagonal, with height and width about equal; the upper 



j,j^ J extremities truncated by the interradial and anal 



plates. Primary radial plates subequal in size, the 



first and third having a general pentangular form 



and the second quadrangular. Supraradial series 



consisting of fourteen to sixteen plates (sometimes 



less), large in the lower part, becoming gradually 



smaller above, the upper ones about five times as 



wide as high ; ther lower larger plates attached to 



the calyx and dome by the intersupraradial and 



summit plates, while the upper smaller plates are 



Diagram of GiT/ptocrinm free and bear tentacula. Interradial and anal 



JVealh, showing the basal 



to ^ether"wffh those ?ft1fe P^^^^^ ^^^7 numerous ; thosc of the middle range, 

 SfurcationT/the'armS passing from the subradial plate upward, are 

 SgemeSS^the'^piaTes largest; the plates between these and the ray are 

 of the anal area. small, some of them minute. In the anal area the 



number of plates is from fifty to sixty ; in the interradial series, from 

 forty to fifty ; and in the intersupraradial areas, twenty or more. 



Arms composed of a single series of very short plates, higher on 

 one side than on the other, and bearing tentacula on the longest 

 sides only : tentacula long and slender. 



Surface of radial plates marked by an elevated rounded ridge, 

 which bifurcates on the first and third radials, the branches passing 

 to the subradials and thence to the basal plates. No other surface- 

 marking seems to have existed, except the appearance of a finely 

 granulose texture. 



This species differs from G. decadactylus of the same geological 



* For obBervations on the relations of Gltptocrinus and Gltptasteh, pec Travmctions of the 

 Albany Institute^ Vol. iv. 



