146 PALAEONTOLOGY OF ILLINOIS. 



should give us some suggestions respecting its affinities. From as careful an 

 examination as could be made without preparing sections for the rnrcroscope. 

 Prof. Verrill writes that he thinks it most probably a sponge, and not a coral, 

 which view we have adopted on his authority. Prof. V. says he is not ac- 

 quainted with any nearly allied genus, but that it is remotely allied to some of 

 the Jurassic forms. 



So far as known at present, the range of this genus is from the Kinderhook 

 division of the Subcarboniferous series to the Chester limestone of the same. 



Sphenopoterium enorme, M. and W. 



PI. 14, Fig. la, lb. 



Sphenopoterium enorme, Meek and "Woethen, Oct., 1860. Proceed. Acad. Nat. Sci., 

 Pbilad. p. 448. 



Small, sub-globose or obtusely subturbinate ; irregularly 

 rounded and apparently retaining remains of a scar of attach- 

 ment at the base. Cells four or more, rounded, conical, of 

 moderate depth, and rather irregularly disposed. Surface 

 strise, rather distinct, and broken up into irregular granules. 

 Length or height, about 0.48 inch; greatest transverse diam- 

 eter, about 0.43; breadth of cells, near 0.18 inch. 



Locality and position : Eockford, Indiana, Gronialite bed, of the Kinderhook 

 group, Subcarboniferous series. Also, in same horizon at Clarksville, Missouri. 



Sphenopoterium enorme, var. depressum. 



PI. 14, Fig. 2 a, 2 b. 



This form may possibly belong to a distinct species, but with 



the specimens we have yet seen, for comparison, we are inclined 



to regard it as only a variety of the last. It differs mainly in 



being more depressed, and in having its base flattened, or 



truncate instead of irregularly conical. Its cells are also more 



regularly disposed in a quadrangle, and more nearly on a plane. 



Locality and position: Salt Lick Point, Monroe county, Illinois, in same 

 position as last. 



