39 



ti'ii sides. II is followed hy two elf)ii,L(ate([ |)lMtes in the second 

 raiif^e, beyond which we have been unable to see tlu' sutures. In the 

 inter-secondary areas one ])late is followed by two in the second 

 ranjre. and tliose 1)\' three in the third ranye. heyoiid which silici- 

 tication has destroyed the sutures in onr s|iecinicus. 



The vault is low. liut oui' specimens are not prcsei'ved to throw any 

 liiclit u])on it. 



The u'reater nundier of specimens are found silicilied, and it is 

 rare to hnd the crinoidal structure exposed. It is a remarkable spe- 

 cies and hears little '>]■ no resemblance to the t\pc spe<-ies. Indeed 

 no one would suspect that they could helouLi to the sanu' n'cnus. 

 without haviu!.;' compared them with theucneric formula. The two 

 prinuiry radials in each s|)ecies alone ally them with each other. 



l-'ound by (tco. K. (Ircene in the Hamilton (irou|). ncai' Charh-s- 

 town. Indiana, and now in the collection of ^Vm. I'', i'l (iurley. 



Fa.milv EH( )I)()('RINIDJ-]. 



KHODOCRlNrs 1)()C(;L.\SSI. U. S[). 

 Plate 111. J'/i). J. <''-ll!l'>iis itrcit on tin- left. 



S[)ccics nu'dium or above medium size. Calyx bowl-shajjcd. or 

 subcyliudrical. radial ridges not defined. Plates sculptured anil 

 more (U- less pyraniindal. Basal cavity deep. Cobimu nu'dinm size, 

 round, and composed of plates of eipial length. 



Basals form a cone, witliin the calyx, into wliich the end of the 

 column is inserted. Subradials slightly larger than the hrst primary 

 radials and sculptured |)yrainidal. First primary radials pyramidal, 

 heptagonal and hexagonal. Second primary radials about one fourth 

 as large as the lirsl. nearly as long as wide, pentagonal. Third prim- 

 ary radials about the size of the second, hexagonal, and sup- 

 port on each of two upper sides, the seconilary radials. There are 

 three secondary radials in each scries, the first one being tlie larger 

 and the last out' being axillary. There is a plate, resting in tlu^ 

 angle, formed at the juction of the first secondary radials, which 

 lias the appearance of belonging to a radial series and the thiril 

 plate above being axillary. Pint here an explanation beconu-s neces- 

 sary. Our specimen is in jured. at this ]ilacc, as shown in ihe'iilus- 

 tration, and we cannot determine t'xactly how the arms attached. 

 The ray we are describing is on the right of tlie azygous area and 



