Report of the State Geologist. 261 



a primary series of low, narrow ridges, intersected by a secondary series. 

 Each of the four quadrules thus formed contains sixteen meshes of 

 the third degree and sixty-four meshes of the fourth degree. 



The species may be distinguished from D. Ravdalli which it 

 somewhat resembles in the characters of the reticulum by the more 

 elongate cup, the narrow and fainter ridges of the first and second 

 order and the larger squares made by the intersection. 



The length of the original is 135 mm. ; width at the basal end 50 mm., 

 at the apertural end, 60 mm. 



Formation and locality. — In the Chemung sandstone at Alfred, Alle- 

 gany county, N. Y. 



DiCTYOPHYTON ? (PhRAGMODICTYA) HaLLI, sp. U.* 



Gup usually small, narrowest above the base and rapidly expanding 

 to the aperture. The base sometimes appears to be acute but in 

 many specimens the lower extremity is broad, flattened, slightly con- 

 cave or convex, as though crossed by a septum. Reticulum, composed 

 of a primary series of cancellating ridges (spicular bands?) which 

 make elongate rectangular meshes, nodate at tlie points of inter- 

 section; a secondary series of similar ridges is apparent under good 

 preservation; within the quadrules formed by the crossing of these 

 ridges, is a very finely reticulate mesh. 



The general exterior character of the reticulum in this species is 

 very similar to that in D. rude. 



The species is, however, well characterized by its small size and 

 slender habit of growth, as exemplified in fifty individuals from the 

 same locality, and by the peculiar nature of its basal extremity. 



The dimensions of an average specimen are, length, 85 mm. width 

 across the aperture, 50 mm.; width across the base, 25 mm.; least 

 width, 18 mm. 



Formation and locality. — In the shales of the Chemung group at 

 Wellsville, Allegany county, N. Y. 



AcTiNODicTYA, gen. nov. 



Amorphous or explanate, surface generally slightly convex, spread- 

 ing, uninclosed forms, irregularly reticulated by strong bands of 

 circular spicules. 



The stronger bands are oblique to the general direction of the 

 frond, with shorter radiating bands, giving the intermediate sj)aces a 

 stellate character. An extremely fine rectangular reticulation cover- 

 ing the entire surface. 



*DiPcovered by Mr. E. B. Hall of Wellsville, to whom I am indebted for the specimens 

 described and In whose honor the name is given. 



