382 THE CEINOIDEA CAMERATA OF NORTH AMERICA. 



wider than long, larger than both costals together. Co,stals nearly equal in 

 size ; the first quadrangular, wider than long ; the second heptagoual, a little 

 -wider than the first. Distichals two, transversely arranged ; those of the 

 three anterior rays followed by four to five short palraars, which support the 

 free arms. The palmars of the two lower rows are as large as the distichals 

 and resemble them in form, the upper ones curved like arm plates and 

 smaller. The two posterior rays have five to six arms, — exceptionally 

 seven, — the other rays invariably four. In the two former, either both outer 

 palmars of the second row are axillary, or only the one facing the anal side. 

 Arms long, but comparatively thin ; rounded at the proximal end, slightly 

 flattened at the distal one, and composed of two series of transverse pieces 

 Tinited by a zigzag suture, each plate covered with two delicate nodes 

 arranged into longitudinal rows. Interbrachial plates : 1,2,1. Anal piece 

 narrower and longer than tlie radials ; followed by three or four plates, and 

 these by four to five others of irregular arrangement. Ventral disk hemi- 

 spheric ; the plates tuberculous and of similar size, except those at the pos- 

 terior side which are somewhat smaller. Anal tube very long and stout, 

 extending far above the tips of the arms; the plates rather lai-ge, pentagonal 

 or irreo-ularly hexagonal, and each one covered with a sharp central node. 

 Column large, the nodal joints angular at their edges, and considerably 

 wider than the intervening ones, which, however, increase in width as they 

 pass downwards. 



Horizon and Locality, — Keokuk group ; Crawfordsville, Ind. 



Types in the Lyon collection. 



Remarks. — This species is labeled in several collections Eretmocrinits 

 magnificus, which is a totally different species. "White's Actinocrinus Wachs- 

 muthi is identical with this species. 



Batocrinus mundulus (Hall). 

 Plate XXX. Figs. Jfa, I, and 5. 



1S59. Adinocrimts mundulus — Hall; Suppl. Geol. Rep. Iowa, p. 39. 



1881. Batocrinus mundulus — W. and Sp. ; EeTisioa Palfeocr., Part II., p. 167. 



Syn. Actinocrinus similis — Hall, 1S59 ; Suppl. Geol Rep. Iowa, p. 40. 



Syu. Batocrinus similis — M. and W. ; Geol Rep. Illinois, Vol. V., p. 308. 



A small species. Calyx higher than wide ; the dorsal cup gradually 

 spreading; its base broadly truncate; the sides straight or a little convex. 

 Eadials and brachials marked by transversely arranged, obscure angular 



