Ao^elacuuis, hoibrookL 



GENUS AGELACINUS, Vanuxem. 

 A<;klacrinus holbrooki James. 



Fi^, A. Aeelactiniis holhrooki, James, tvpe specimen natural size, as seen from 

 above. Fiw. B, outline, side view of same specimen, showing the dome shaped eleva- 

 tion. 



A. holbrooki. James. Tk^^ Paleontologist^ Jtdy, 1878. 



Body circular, subglobose. Disc composed of many thin 

 plates, those in the interradial areas pentagonal or hexagonal, 

 outside squamitorm, imbricating; margin of the disc composed 

 of numerous small cuniform and various other shaped plates. 

 Arms or rays not raised above the surface of the disc: four 

 sinistral and one dexlral rays, each composed of two rows of inter- 

 locking pieces ; ends of rays curving quite sharply upward and 

 inward, making nearly a semi-circle, to near the center of the in- 

 terradial areas, and terminating in a blunt club-shaped form. 

 Ovarian aperture situated subcentrally in the area between the 

 dextral and one of the sinistral rays, depressed and composed of 

 ten cuniform pieces and an outer row of small thin plates, placed 

 apparently on their edges. The end of the dextral ray passes into 

 or against the plates of the ovarian aperture. 



Diameter of type specimen, shown in the above figures, A. and 

 B. natural size, at the base i;^ inches, and measuring from side to 

 side over the crown if inches; convexity |^ of an inch. 



This species differs from A. cincitmatienses, Roemer, as defined 

 and figured by Meek and by Hall, in the shapes of the interradial 



