274 DlCTYOSPONOID.«. 



PLATE XXXVIII. 

 HYDNOCERAS, Conrad. 



Page 95. 

 (See Plates II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XXXIII, XXXVI, XXXVII, XXXIX, XLVI.) 



Hydnoceras tuberosum, Conrad. 



Page »7. 

 (See Plates II, III, IV, V, VI, VII, VIII. ) 



Figures 1, 2. Opposite sides of a short compressed specimen of somewhat 

 irregular growth and unusual in the number of nodes (eleven) in the 

 second and third horizontal rows. 

 Lower Chemung. Brown liill colony, near Cohoaton, New Yorh. 



THYSANODICTYA, gen. nov. 



Page 125. 

 (See Plates XIX, XXIII, XXIV, XXV, XXVI, XXVII, XXXIX, XL, XLIt, LIII.) 



TlIYSANODICTYA QUASILLUM, Sp. UOV. 

 Page 131. 



Figures 3, 4. Opposite sides of a specimen figured to illustrate the extreme dif- 

 ference in retention of the reticulum possible in the same specimen. 

 In figure 3 the finer net- work is wholly obliterated and only the coarse 

 primary meshes have left their impression on the sandstone cast. 

 On the other side (figure 4) the primary bands are but obscurely 

 visible while the minute ultimate meshes of the reticulum have left 

 their impression on the thin shaly coating of the sandstone cast. 

 Chemung group. Wenton Mills, Cattaraugus county, New Yorh. 



TlIYSANODICTYA TURRICULA, Sp. nOV. 

 Page 135. 



Figure 5. A coarsely reticulate specimen lying in its matrix and showing the 



basal diaphragm wth some of the long and slender lateral tufts. 



The species is somewhat variable in shape and, in this instance, is 



swollen about the aperture. 

 Figure 6. A specimen which is essentially entire and gently tapers from base 



to aperture. It retains the basal disc and portions of the lateral 



tufts. 



Chemung group. Isckna, New Yorh 



