3IO NEW YORK STATE MUSEUM 



a slender telson spine with longer, slender and apparently curved 

 cercopods, the other with a heavy telson much longer than the 

 cercopods which are short bladelike and longitudinally striated. 

 These are both from the black shales of the grit and neither can be 

 more exactly determined generically than by the term Ceratiocaris. 

 In the gray shales above the grit have been found a number of 

 fragments of bodies no one of which gives any clue to its exact 

 outline save that they are sometimes rounded at one extremity 

 and all are ornately engraved by longitudinal anastomosing lines 

 or groups of continuous or broken lines as illustrated on plate 8, 

 figures 14 to 21. I think there is no reasonable doubt that these 

 are carapaces and parts of segments of Phyllocarids, but if so, of 

 a type of structure heretofore unknown. Future investigations will, 

 it is hoped, elucidate the nature of these peculiar bodies. 



In the Pittsford shales there are Phyllocarids which I have 

 described under the names Ceratiocaris precedens and 

 Emmelezoe decora and it is usual to find these crustaceans 

 associated with the merostomes in all the Upper Siluric occurrences 

 of the latter. 



