Spkcies op thk CiiKMuxa Group. 75 



W. At the apex of the best preserved specimen is the impression of a 

 short basal tuft of spicules. 



Dirmmwm. One example measures in length, exclusive of the basal 

 tuft, 36 mm. ; its median diameter is 4.5 mm. and its apertural diameter, 3 ram. 

 In a second specimen two individuals lie side by side, one of them measuring 

 37 mm. in length, with a median diameter of 7 mm. and an apertural diameter 

 of 4 mm. This specimen has been somewhat flattened. 



Locality. In the sandstones of the upper portion of the Chemung group 

 afWellsviUe, N, Y. (Collection of E. B. Hall.) 



DiCTYOSPONGIA ETTMORPIIA, Sp. nOV. 

 Plate xv, Pigs. 1-3. 

 Sponge small, slender, elongate-subfusiform, expanding for about one- 

 fourth its length from the apex, thence upward with parallel sides, contracting, 

 somewhat toward the aperture. Surface smooth ; reticulation very fine, com- 

 posed of minute subequal rectangular meshes, whose ordinal arrangement is 

 not clearly defined. 



Two specimens of this species upon the same slab of sandstone, measure 

 80 and 84 mm. in length, each having a maximum width of 15 mm. In the 

 smaller individual the aperture is retained, but in neither is the basal 

 extremity entire. The species is distinguished from the other forms here 

 described by its more rapidly expanding and broader cup. 



Locality. In the upper beds of the Chemung group at Wellsville N Y 

 (Collection of E. B. Hall.) 



DiCTYOSPONGIA SIR^A, Sp. nOV. 

 Plate xlii, Figs. 4, 5. 



SpoifGE rather small, expanding gradually, but with greater rapidity on 

 one side than on the other, thus giving the cup a semi-crescentic outline, a 

 feature persistent in all specimens. The shape is thus long and slender, the 

 aperture being somewhat narrower than the parts immediately belovv it. 

 The lower portion terminates in a long, narrow rope of anchoring rods whose 

 length is nearly if not fully as great as the body of the sponge. 



The reticulum is composed of a net- work of small quadrules of generally 

 uniform size, not often distinctly retained. The surface shows no nodes or 

 other irregularities. 



Ditnemioiis. A specimen entire except for a part of the anchoring rope, 

 measures in length, from base to aperture, 72 mm., the ^vidth of the aperture 



