244 Dld'YOSPONGID^. 



PLATE XXIIL 

 TIIYSANODICTYA, gen. nov. 



Page 125. 

 (See Plates XIX, XXIV, XXV, XXVI, XXVII, XXXVIII, XXXIX, XL, XLII, LIII.) 



TiiysANODicrrA rudis, Hall (sp.). 



Page 128. 

 (See Plate XIX.) 



Figure 1. An essentially entire individual, showing the form of the aperture, 



the cylindncal body and coarse and line reticulation. 



Chemung group. Isehua, Cattaraugus county, New York. 

 Figure 2. A basal disk, probably of this species, showing the excentric apex, 



the concentric and apparently i-adial striae. 



Chemung group. Alma, Allegany coimty, New Yorlc. 



Figure 3. A portion of a specimen believed to be of this species ; showing 

 differences in the preservation of the reticulum on various parts 

 of the surface. 



Figure 4. The opposite side of the same specimen lying in its matrix and 

 showing the projection of both vertical and horizontal erect lamellae. 



Figure 5. Basal view of this specimen. 



Chemung group. Wdlsvtlle, New York 



Figure 6. The original specimen of this species, Avhich is a nearly entire 

 individual showing the form and size of the primary quadrules and 

 a part of the finer reticulation. 

 Chemung group. Zittle Genesee, Allegany county, New York. 



Thysanodictya Johnstoni, sp. nov. 



Page 130. 



Figure 7. An entire specimen, bent upward at the base. The body of the 

 cup is covered with low nodes of shaly matter Avhich appears to have 

 formed in a concretionary manner about irregularities or projections 

 upon the surface of the reticulum. The character of the basal disk, 

 its eccentric apex and nodose j)eriphery are well known. 



Figure 8. A basal disk with a highly irregular reticulum and without 

 defined apex. This appears to be a normal and not accidental 

 condition. 

 Chemung group. Wellsville, New York, 



