l8o NEW YORK STATE MUSEUM 



of the. genus Hydnoceras, which bears in itself the characters of 

 the typical genera; Dictyospongia, the smooth sponges; Prismo- 

 dictya, the prismatic sponges; and Ceratodictya, the annulated 

 sponges; and upon these characters assumed in succession, are 

 imposed the nodes which, generally speaking, are later than the 

 other features (although they may appear at times on the prism- 

 angles without the intervention or presence of the annulations) ; all 

 of which indicates the fact that the nodose sponges of this type 

 are the extreme terminus, the final term of development along these 

 lines. They are the most advanced, the most highly accelerated, 

 the most extravagant in ornament, and carry most conspicuously 

 in themselves the evidence of the path they have followed in their 

 development. Whether or not the nodose sponges are the last to 

 survive in this peculiar group is quite another matter; upon that 

 we are not prepared to speak positively. They are certainly the 

 most abundant of all the known representatives of the stock, but 

 logically the last to survive would be the stronger type, and theo- 

 retically the stronger type is the simplest. 



The species under consideration has no outstanding specific name. 

 It can not be brought into specific relationship with any other form 

 now described, and for this reason it is herewith given the desig- 

 nation, Hydnoceras walcotti, in honor of the dis- 

 tinguished secretary of the Smithsonian Institution. 



2 Chemung Sponges from the Vicinity of Erie, Pa. 



Through the courtesy of Mr E. J. Armstrong of Erie, Pa., I 

 have received interesting indications of heretofore undescribed 

 species of Dictyosponges from the neighborhood of his city. Both 

 of the species are represented by more than one specimen, and each 

 is of very exceptional interest as presenting a type of structure, 

 broader than specific, which has not heretofore been recognized 

 from the great sponge fauna of the later Devonian Period. 



The first of these may be designated and described as : 



CERATODICTYA ORYX Sp. UOV. 



(Plate 2) 



The term Ceratodictya was introduced by Hall and Clarke for 

 the purpose of embracing a series of rather commanding species 

 characterized by simple or duplicate annulations but without retain- 

 ing either the prismatic or the nodose features of the surface. 



