FOSSILS OF THE r.UULlNCTOX (IRoCP. 343 



or both bifurcating again on the first piece, thus making 

 from >eveu to ciirht arms to each ray, or from thirty-five 

 to forty in the entire series. The single piece below and 

 the first above each division is slender, rounded, and more 

 or less constricted, and generally two or three wedge-formed 

 pieces follow the latter before the commencement of the 

 double series of alternating pieces, above which the arms 

 are a little wider and of moderate length ; vault unknown : 

 proboscis very slender at the upper end, and apparently of 

 about the same length as the arms. 



Surface of all the body plates deeply excavated at the 

 corners, and prominent in the middle, the prominence of 

 the first radials usually forming a transverse ridge, from 

 which a single more or less defined vertical ridge ascends 

 the second radials to the middle of the third, from which 

 it bifurcates and continues to the secondarv radials. 







Hight of body to the top of secondary radials, about 

 0.22 inch : breadth at the top of secondary radials, O.iO 

 inch : length of arms, if straightened out. about 0.70 inch ; 

 breadth of same, at the widest part near the middle. 0.05 

 inch. 



This little species is allied to A. lucina. Hall, which, before seeing 

 specimens showing the arms, we had supposed to belong to the A. mul- 

 iihrttcJiiutu.'s group, but which is a True Actinocrinites. Our species dif- 

 fers. however, in having the arms more frequently and differently 

 bifurcating, so as to make from thirteen to fifteen more in the entire 

 series. Its arms also differ in not being sukspiuous on their margins. 



Locality and position Lower Burlington beds of Lower Carbonifer- 

 ous, Burlington. Iowa. Xo. 38 of Mr. WACHSMUTH'S collection. 



ixrs scn.i'Tt s. Hall. 

 PI. 4, fig. a. 



Aftinorrinut sculptus. Hall, 1658. Geol. Sur. of Iowa. VoL I. part 2, p. 582. Burlington limestone. 

 Burlington. Iowa. 



A( TIX(X IIIXITES DELK'ATrs. M. tllld W. 



PI. 8. Fig. 2. 

 Aetincerinitti delirafns, MEEK and WoRTHEX. Proceed. Acad. Xat. Sci.. Phila.. Ifefl9, p. 155. 



BODY small, suhturbinate, or widening rather rapidly 

 from tin- somewhat truncated base to the top of the third 



