54 



formula. The aim formula is like D. salt brosu?, but that spe 

 cies has a concave depression below, and is constricted below 

 the arms, and has two interradials in the second range, and 

 very different surface ornamentation. This species cannot be 

 mistaken for any other, either upon superficial examination 

 or upon close inspection of the number and arrangement of 

 the plates. 



Found by Geo. K. Greene in the Hamilton Group, near 

 Charlestowu, Indiana, and now in the collection of Wm. P. E. 

 Gurley. 



DOLATOCRINUS DISSIMILARIS, n. Sp. 



Vlaie III, Fig. 25, basal view; Fig. 26, summit view, Fig. 27, 



azygous side view. 



Species below medium size, depressed or very short. Calyx 

 low, about three times as wide as high, rounding out from a 

 deep basal cavity and spreading, without any constriction be 

 low the arms and having the general form of D. ap 1 atus. Sur- 

 face deeply sculptured. Radial ridges very small and nodes 

 small. The central part of each interradial instead of bearing 

 a node is excavated. 



Basal plates within the cavity of the calyx and extend 

 higher than the base of the free arms, funnel-shaped. 

 First primary radials within the funnel-shaped basal cavity 

 and longer than wide. Second primary radials about twice as 

 wide as long, quadrangular. Third primary radials a little 

 larger than the second, twice as wide as long, pentagonal, 

 axillary, and in each ray adjoining the azygous area and in 

 the ray opposite the azygous area support on one of the upper 

 sloping sides three secondary radials and upon the other a 

 single secondary radial, which is axillary and supports on each 

 upper sloping side two tertiary radials, which arrangement 

 gives to each of these rays three arms. In each of the other 

 lateral rays the third primary radials support on each upper 

 side three secondary radials which give to each of these rays 

 two arms. There are, therefore, thirteen arms in this species. 

 It is the proximal side of each ray adjoining the azygous area 

 that bears the tertiary radials. 



The azygous area is like the other areas. The first plate is 

 somewhat elongated, has nine sides and is truncated by a single 



