250 DlClYOSPONGID.*. 



PLATE XXVI. 



THYSANODICTYA, gen. nov. 



Page 125. 

 (See Plates XIX, XXIII, XXIV, XXV, XXVII, XXXVIII, XXXIX, XL, XLII, LUX.) 



TlIYSANODICTYA APLETA, Sp. IIOV. 



Page 135. 



(See Plate XXVII.) 



Figure 1. Portion of a very large specimen ; drawn from a plastei- cast of a 

 natural mould. 

 Chemung group. Alfred, New Yorh. 



