484 PALAEONTOLOGY OF ILLINOIS. 



Third radials a little longer in proportion to their breath 

 than the second, and presenting a subtrigonal outline, sup- 

 porting on their sloping upper sides, broad, short, rounded 

 arm-pieces. Anal piece about half as wide and nearly of 

 the same length as the first radials, and subquadrangular 

 in form. Surface marked with small pustules, which often 

 become confluent, so as to produce a peculiar corrugated 

 roughness, somewhat similar to the ornamentation we see 

 on the body plates of the true Am/phoracrinus, but coarser. 

 Breadth of body, 3.33 inches; hight of do., 2.20 inches; 

 breadth of base, 0.60 inch; breadth of facet for the recep- 

 tion of the column, 0.85 inch ; do. of largest first radial 

 piece, 1.70 inches; hight of same, 1.30 inches. Thickness 

 of one of the arms at base, 0.70 inch. 



This splendid Criuoid was found by Mr. Green, of the Illinois Survey, 

 with its plates detached and lying near together in the rather soft 

 matrix. After working out the pieces, we succeeded in building up the 

 entire body to the third radials and first arm-pieces, inclusive, except- 

 ing the anal piece, which was not found. It presents a very striking 

 appearance, and is the largest Crinoid we have ever seen. If its arms 

 were as long in proportion as those of some other species of this group, 

 they must have been near twelve inches in length, and with its column, 

 body and arms together, it may have been more than four feet in hight. 

 It is evidently related to Barycrinus magister, Hall (sp.), but differs 

 from that species, the type of which is now before us, in having its sur- 

 face roughened by numerous small pustules, showing a tendency to run 

 together into vermicular markings, with an obscure effort, on some of 

 the plates, to assume a radiating arrangement. It is true, the typical 

 specimen of B. magister consists of only the basal pieces and a portion 

 of the column, but these basal plates show no traces of the peculiar 

 surface markings seen even on the base of our species, while we have 

 before us, from the same original locality, another specimen of that 

 species, consisting of the whole body, in a flattened and crushed condi- 

 tion, and, although the surface of its plates is well preserved, they show 

 no indications whatever of the surface markings seen on our species. 



Those who give a wide latitude to genera will probably not regard 

 such forms as this as being generically distinct from Cyathocrinus ; 

 even if that view should ultimately prevail, however, we should insist 

 upon their separation as a strongly marked subgenus, and continue to 

 write the name of our species CyathocrmiteB (Barycriniis) 



