NEW PALEOZOIC CRUSTACEANS 



BY JOHN M. CLARKE 



I 



BUNAIA — A NEW MEROSTOME CRUSTACEAN 



FROM THE NEW YORK SILURIAN WATERLIMES 



It was to be expected that the Salina formation, above and below 

 the horizon of the salt, would eventually afford evidence of the exist- 

 ence of the crustacean Bunodes or something closely allied to it. 



The Pittsford and Vernon shales of the lower part of the formation 

 have already afforded the genus Pseudoniscus in two species 

 (P. roosevelti Clarke and P. clarkei Ruedemann) and 

 these intimate a combination which is highly suggestive of the 

 Eurypterid-bearing Silurian beds of Oesel, to which the genus 

 Bunodes has been thus far restricted. 



The fossils now before us present certain characters very sug- 

 gestive of Bunodes and, it may be added, also of Hemiaspis, which 

 is a Scottish crustacean of the same geological age. The resemblance 

 between these European crustaceans and the American species is, 

 in general lines, so obvious that their close relationship is clearly 

 indicated, but so far as we understand the new form it is materially 

 different in some structures, and adds some quite important details 

 for this group. 



In the absence of very definite knowledge of the ventral structure 

 of the group with which these creatures have been associated in 

 classification, they have been provisionally brought together with 

 others under the order name Synxiphosura^ with the general subdi- 

 visions (i) Aglaspina and (2) Bunodomorpha, the latter of these 

 combining the following genera: Neolimulus (Silurian, Scotland); 

 Bunodes (Silurian, Island of Oesel) ; Hemiaspis (Silurian, Scotland) ; 

 Bunodella (Silurian, New Brunswick) ; Pseudoniscus (Silurian, 

 Island of Oesel, New York). Of these, only two genera, Bunodes 

 and Hemiaspis, come into present comparison. 



Bunodes, according to the descriptions by Eichwald, Schmidt and 

 Nieszkowski (who termed the fossil Exapinurus) and most recently 



1 Clarke, in Zittel-Eastman's Paleontology, p. 775. 



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