452 



GEOLOGICAL SURVEY OF THE TEERITOEIES. 



Lower Carboniferous Eocks. The genus Argus seems to be the same as 

 Dithyrocaris, although Salter does not express that opinion. Fig. 69'' rep- 

 resents Argus testudineus ; the surface of the body is striated. Dithy- 

 rocaris pholadomyia Salter had a carapace 7 inches long. The genus 

 Argus of Scolder is apparently the same as Dithyrocaris. 



D. tenuistriatus McCoy, Woodward, Geol. Mag. viii. Great Britain. 

 D. belli Woodw. 1. c. Devonian, Gasp^, Canada. 



1>. Neptuni Hall (P^ig. 73), lOth Ann. Rep. State Cabinet, N. York. 75, PI. I, fig. 9, 1863. 

 Hamilton group, Devonian of New York. 





..'■ \^ 



fig. 13.— Dithyrocaris neptuni Sail ; telson and cercopoda, natural size. Trom Hall. 



Hall's figure was made from a cast, no restoration having been at- 

 tempted. From the size of the telson and the cercopods, it is evident 

 that the animal must have been enormous, perhaps between two and 

 three feet in length. 



Genus EhacHURA Scudder, 1878. 



B. unosa Scndd., Proc. Bost. Soc. Nat. Hist. XIX, 296. PI. 9. fig. 3, Za. Marcli, 

 1878. Coal measures, Danville, Ohio, 



