Notes on Some Crustaceans from the Chemung Group of 



New York. 



By John M. Clarke. 



I. A Singularly Ornamented Phyllocarid Genus, Pephricaris. 



By the courtesy of Professor A. R. Crandall, of Alfred university, 

 Alfred, N. Y., and the kindness of Mr. Charles Butts, of the same place, I 

 have been permitted to study specimens of a new crustacean allied to Echi- 

 nocaris, but noteworthy for the extravagant nature of its armature. Of these 

 specimens, two in number, the more complete belongs to the museum of 

 Alfred university and is a sculpture-cast of essentially the entire test, the 

 valves of the carapace being expanded without distortion and the abdominal 

 segments showing, in part, in the posterior hiatus of the carapace valves and 

 thence normally protruding behind. The second specimen, the property 

 of Mr. Butts, is only the echinate margin of one carapace valve. 



The general aspect of the carapace is not unlike that of some species of 

 Echinoca/ris, yet it is devoid of the curved sigmoid carina which characterizes 

 typical species of that genus. 



The carapace valves are broad, their margins curving rapidly outward 

 for about one-half of their length, slowly recurv- 

 ing near the middle and thence more rapidly 

 receding to the posterior extremity. The expanded 

 valves lie with a moderately broad anterior or 

 rostral cleft, but there is no evidence of a separate 

 rostral plate. They are in contact just back of the 

 apex of this cleft, but for only a short distance, as 

 the underlying abdominal segments are partly 

 exposed, a fact which may be due either to this 

 being the normal attitude of the valves, or to casual 

 separation of them, or again to a breaking of the Pephricaris Urripiiata, Chemung 

 edges of the cast which is not altogether clear at this 



place. The surface of each valve is divided into two convexities by an oblique 

 depression beginning at the dorsal edge just back of the middle and extend- 

 ing backward with gentle obliquity. This groove does not reach the margin 



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