234 DiCTYOSPONGIDJE, 



PLATE XVIII. 

 PRISMODICTYA, geu. nov. 



Page 79. 

 (See Plates XVII. XIX, XX, XXI, XXVII, XXXIII, XXXIV, XXXV, XXXVI, XLI, XLII, LV.) 



Pbismodictya baculum, Hall (sp.). 



Page 81. 



Figures 1, 2. Opposite sides of an incomplete sponge which is referred to 

 this species. 

 Chemung group. Alfred, New York. 



Figure 3. The type-specimen, an incomplete cup, slender near the base and 

 expanded toward the aperture. The specimen is a sharp internal 

 cast, showing the regularity of the primary reticulation. 

 Chemung group. Wellsville, New York. 



Prismodictya Coneadi, Hall (sp.). 



Page 91. 

 (See Plate XIX.) 



Figure 4. Lateral view of the original specimen; showing the regularly 

 expanding form, the character of the reticulation and, over the 

 upper part of the sponge, the somewhat irregular tendency to the 

 formation of nodes upon the prism-faces. 

 Chemung group. Handolph, Cattaraugus county. New Yorh. 



CLATHROSPONGIA, Hall. 



Page 121. 

 (See Plates XIV, XV, XXI, XXV, XLIX, L.) 



Clatiikospongia (?) TOMACULUM, Hall (sp.). 



Page 123. 

 (See Plate XXI.) 



Figures 5, 6. Opposite sides of the type-specimen, which is a portion of a 

 large, very gradually expanding sponge with low and nan-ow prism- 

 faces. The reticulation is coarse and over most of the exposed 

 surfaces shows a prevalence of square meshes. The curvature of 

 the specimen is probably accidental. 

 Chemung group. Alfred, New Yorh. 



