276 



DlCTYOSPONGn>.iE. 



PLATE XXXIX. 



HYDNOCERAS, Conrad. 



Page 95. 

 (See Plates H, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XXXIII, XXXVI, XXXVII, XXXVIII, XLVL, 



Hydnocekas multinodosum, sp. nov. 



Page 106. 



Fi<'-ure 1. Fragment of a large individual bearing three horizontal rows of 

 nodes and showing the unusual number of nodes in each row. 

 Chemung group. Cotton hill, near.Avoca, New Yorh. 



TIIYSANODICTYA, gen. nov. 



Page 135. 

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



Thysanodictya iiermenia, sp. nov. 



Page 133. 

 (See Plates XXVII and XL.) 



Figure 2. A large basal disc with its undulated periloph or peripheral 

 expansion. The reticular net- work is sharply defined and it is seen 

 that the two sets of reticular bands here intersecting are those which, 

 passing upward over the vertical surface of the frond, produce both 

 horizontal and vertical bands. 

 Chemung group. Hiiisdale, Cattaraugus county, New Yorh. 



