NO. 3 ON THE FOSSIL CRINOID FAMILY CATILLOCRIX IDAE II 



show that even these interradial sutures, of the presence and exact 

 position of which we are always perfectly sure, are so compressed, 

 or modified by the tendency to fusion, as to be very indistinct at the 

 interior, and sometimes completely invisible. This happens in one 

 case where the plates along the line of an adjacent suture have actu- 

 ally separated. The compression would be even greater in the base, 

 where the surface is overgrown by the large column. Therefore the 

 fact that sutures cannot be seen in a number of specimens in the posi- 

 tion where they should be, must not be taken as conclusive of the 

 absence of a primary division among the plates ; and a single specimen 

 in which the sutures can be seen is of more weight as evidence than 

 several in which they cannot. 



There remain, however, still to be considered the statements 

 in the original descriptions by Shumard, both generic and specific, 

 indicating the presence of three rings of plates in the dorsal cup of 

 Catillocrinus tenncssceac, which have hitherto been disregarded. At 

 that time there were no controversies about the " Dicyclic " or " Mono- 

 cyclic " base, which might influence opinion one way or the other. 

 Shumard was a careful observer, and it has seemed to me improbable 

 that he should have described a structure like this with such particu- 

 larity without having some persuasive evidence in support of his 

 interpretation. To say that the base was " small, concealed by the 

 column, situated in a deep cavity and projecting into the interior in 

 form of a low cone," was too definite a statement to be founded on 

 mere supposition. Therefore when I acquired the Hambach col- 

 lection at St. Louis, I looked with special interest among the Shumard 

 types which it contained for the originals of his Catillocrinus descrip- 

 tion ; and to my great satisfaction found his two specimens from 

 Button Mould Knob, Kentucky, one of which agrees with his state- 

 ment above quoted in every particular. Other material contained in 

 collections made for me at the type locality and at White's Creek, 

 Tennessee, and those of S. S. and Victor W. Lyon, also acquired, have 

 furnished considerable confirmatory evidence ; so that I am now 

 enabled to present the facts with a wealth of detail unusual in so 

 rare a form. 



In the Shumard type specimen the low cone lies at the bottom of 

 the visceral cavity on the inner floor of the calyx, invisible from the 

 dorsal side — not because concealed by the column, as Shumard 

 stated, for the proximal columnal is not attached, but because ob- 

 scured by fusion, as elsewhere explained. It consists of three nearly 

 equal plates, separated by perfectly distinct sutures which can readily 



