30 



BULLETIN OF THE LABORATORIES 



Kinderhook of 111. and P. swallovi, from the Chouteau limestone of 

 Missouri, but seems quite distinct. 



From nodules in shale at Moot's run, also in the shales containing 

 the same. 



Pleurodictyujn Prohlematicum, Goldf. 

 (Plate VIII, Fig. 15.) 



" Corallum depressed, sub-hemispherical, or semilenticular ; the 

 under side concave and provided with an epitheca, the upper convex. 

 Corallites somewhat irregular in size and form, more or less angular, 

 often hexagonal, short, increasing rapidly in size and so distinctly ra- 

 diating from the middle upwards and outwards, that those of the lower 

 series lie nearly or quite parallel to the concave base, and even decline 

 as they extend out from near the middle to the periphery — those rising 

 from near the middle shorter than the others; connecting pores as in- 

 dicated by their casts, rather numerous, and apparently irregularly ar- 

 ranged, sometimes passing through the corners as well as the sides of 

 the walls between the corallites." 



A considerable number of this interesting compound coral were 

 found by W. F. Cooper, in the upper layers of freestone near congl. 

 II, in a condition similar to that described by Meek and VVorthen. 

 The "coarse, friable sandstone," referred to the Onondaga section of 

 the corniferous group by the Illinois geologists seems to belong at a 

 higher horizon as first supposed, at least the presence of the same form 

 in the Waverly group, pretty well up in the series, lends probability to 

 this suggestion. 



Orhicidoidea sp? 

 (Plate VIII, Fig. 14.) 



A large species of Discina-like appearance is common in the shales 

 of the middle Waverly and has been usually referred to D. newberryi, 

 Meek. As only the dorsal valve is known and this is larger than the 

 type, we prefer to defer identification. There is a ridge rather than a 

 slit, as in Discina and the shell is usually distorted. 



