i? VW. i;i' i'<'i;r ok i'K()(;kkss. c. k. bkkciier. 



fenvd tlieiH lo the uvims ONcirrs. Only the separated jior- 

 ti(»ns of rlit' nilid rail were then known, and this reference 

 was nor unnatural. 



18.")(). — These fraunients were ascribed to Ptkkygotus and 

 consrimred as a sub-genus Li'n'TociiKLEs by Professor Mc- 

 Coy. In the same publication he proposes the genus Cera- 

 . Tioc.vKis, and describes rwo species. 



ISol. — The following year these species are again de- 

 scribed by Prof. McCoy and properly classed with the 

 Phyllopoda, which has since been the receptacle for all fossil 

 forms of a similar nature. 



1S62. — In 1852, Professor Hall made the first announce- 

 menr in America of the discovery of fossils similar to those 

 described by Prof. Agassiz as Onchus miircJdsoni^ and 

 described the species Onchus deweyi, from the Niagara 

 group of Xew York. {Pal. JSf. Y. Vol. it, p. 320.) 



185 J. — M. J. Barrande x^ointed out the essential identity 

 of the fossils described under the names of Onchus and 

 Lki'TOCIIKLKS. with the telson and movable spines of Cera- 

 TiocARis, and suggests that these names are superfluous. 



Since this time a number of new genera have been estab- 

 lislied both in America and abroad, of which only those 

 will here be noticed which lead directly to the species of 

 the ])resent paper. 



1S6.J.— In the 16th Report of the New York State Cabinet 

 of Natural History, Professor Hall described four species 

 of this order and referred three of them to the genus Cera- 

 TiocARis. Two of these have since been recognized as 

 having been described from different portions of individuals 

 of the same species, and are now united under one species. 



1876. — In 1876 the same author again illustrated these 

 species and refered to one as Ceratiocaris {Arlstozoe) iiunc- 

 tdtijs, and suggested that the specimens designated as Cera- 

 tiocaris armatus were probably identical with it. {Illus- 

 trations of Devonian Fossils, j)^- ^■^•) 



1879. — Dr. A. S. Packard recognizes the importance of 

 Nebalia and its fossil allies and their relations to the de- 

 capods, and ] proposes the order PJtyllocarida for their re- 

 ception. {Zoology American Science Series, p. 103.) 



