EXPLANATION OF PLATES 225 



of one adult with portions of five other individuals in vari- 

 ous stages of growth. Noteworthy features of the adult 

 are the form and direction of the rays, the large subinar- 

 gimal and small marginal plates and the sculptured surface 

 of the inter-radial plates. The two very young individuals 

 are specially interesting, as showing the relative width of 

 the marginal area and the straight rays abutting against 

 the broad border, x 2 



This is not a reproduction of the figure "given by Hall, in the 24th 

 report of the New York state museum, but is a new drawing. 



Hamilton beds. West Hamilton, Madison oo. N. Y. 



Agelacrinites buttsi sp. nov. 

 p. 196 



Fig. 



7 A cluster of individuals attached to a shell of Ptyohopteria. 



Natural size 



8 The largest of the individuals x 2. Showing the very broad 



border composed of ismall imbricating plates, R 1-4 contra- 

 solar, R 5 solar and the imbricating interradial plates 



9 A you*nger individual, in which the border is relatively much 



broader and the ravs direct, x 2 

 Supradevonic sandstone (Cattaraugus beds) Mt Moriah, Cat- 

 taraugus co. N. Y. 



