NEW AND INTERESTING FOSSIDS FROM THE DEVON- 

 IAN OF NEW YORK 



BY 



Axel Olsson 



The new crinoids described in this paper are from the Upper 

 Devonian rocks of southern New York, from which only a few 

 species are known. This is due to the rarity of their calyces 

 since whole beds in the Portage and Chemung formations are 

 often entirely made up of crinoid joints and stems. Because of 

 their occurrence in sandstones and sandy-shales, the calcareous 

 portions of the fossils have usually been entirely removed by 

 percolating waters. From these moulds thus formed, beautiful 

 casts may be made by means of gutta percha. By this method 

 the most minute details may be reproduced, but unfortunately 

 these casts become brittle with age. The phyllocarid Echinocaris 

 Punctata (Hall) Whit., is mentioned because of its occurrence in 

 a new horizon. The writer wishes to express bis acknowledge- 

 ments to Professors H. S. Williams and G. D. Harris for the 

 loan of the crinoids and for various helpful suggestions in the 

 course of the work. 



Trichotocrinus, n. sub. gen. 



Dorsal cup agreeing in all its characters with Melocrimis. 

 Resting upon the upper sloping snrface of the second (2nd) 

 costals are two rows of pentagonal shaped distichals which form 

 part of the dorsal cup. From these are continued free rays, 

 which are united throughout their length and give off from each 

 fourth (4th) or fifth (5th) brachial plates, small biserial armlets 

 bearing pinnules. Further up in place of a pair of these armlets, 

 two lateral branched are formed which being oppositely arranged 

 and together with the main trunk produced a trichotomy. The 

 lateral branches in turn give off from each fourth (4th) or fifth 

 (5th) brachial plates, armlets which appear to be uniserial and 

 which in turn give off pinnules. A deep vental groove is con- 



