Spk(!Iks of the Portage Group. 71 



to which they have been subjected, i)ro])a])ly the former wlightly increjised and 

 the latter as much diminished. 



Locality. In the flags beh)\v the Portage sandstones in the east-side ravine 

 at Varysburg, Wyoming county. (Collected by D. I). Luther.) 



CLEPSYDROSPONGIA, gen. nov. 



Sponge subcylindrical ; subequally expanded at both base and aperture ; 

 contracted medially. Apertural margin simple, not explanate. Mode of 

 attachment at the base not known (possibly by a transverse disk or diji- 

 phragm as in Thysanodiotya and Phbagmodictya). Surface with transverse 

 rows of low, pointed nodes, as in Hydnoceras. 



Type, Clepsydrospongia matutina, sp. nov. 



Clepsydeospongia matutina, sp. nov. 



Plate xxxiv, Figs. 1, 2. 



Sponge of moderately large size ; originally subcylindrical. Diameter of 

 basal and apertural extremities subequal; constricted medially so that the 

 median width is about two-thirds of that at the ends. Both basal and aper- 

 tural extremities appear to end abruptly, the latter showing a regular and but 

 slightly expanded margin. The basal edge is not defined with precision but 

 to all appearances it terminates simply as in the case of the aperture, although 

 a transverse basal disk may have existed. 



The surface shows evidence of five horizontal rows of nodes of the same 

 character as those of Hydnoceras. The lowest of these is highly obscure ; 

 the second is somewhat more pronounced, as shown along the edges of the 

 specimen. These lower rows are separated by a furrow so shallow that the 

 surface in this region was virtually cylindrical. The third or median row of 

 nodes is the most conspicuous of all. It is separated from adjacent rows by 

 broad and moderately deep constrictions. The nodes also, are more strongly 

 developed than elsewhere on the surface, are elongate and rather low. Both 

 in this row and that following above, there are ten nodes, varying among 

 themselves in size ; those of the fourth row are not as strongly pronounced 

 as those in the median row. The nodes of the fifth or apertural row 

 are hardly discernible, and thus the apertural one-third of the cup and the 

 basal one-third have a very similar aspect. These nodes are all conical and 

 tufted. 



