530 



CRUSTACEA. 



[ARC. ASA. 



vermiformis, Meek, 1872, Proc. Acad. 

 Nat, Sci. Phil., p. 335, and Ohio Pal., 

 vol. 2, p. 321, Subcarboniferous. 

 Arctinurus, Castelnau, 1843, Syst. Syl., p. 21, 



syn. for Lie-has. 



Arethusina, Barrande, 1852, Syst. Sil. Boh. 

 Not yet known as an American genus. 

 (?) americana, Walcott, 1885, Monogr. U. S. 

 Geo. Sur., vol. 8, p. 62, Potsdam Gr. 

 Founded upon a fragment of a cephalic 

 shield which does not belong to this 

 genus. 



Arget, Goldfuss, 1839, Nova Acta Phys. Acad. 



Caes. Leop. Nat. Cur. Not American. 



Arionellus, Barrande, 1852, Syst. Sil. Boh., 



syn. for Agraulus. 



bipunctatus, see Agraulus bipunctatus. 

 conrmts, see Agraulus convexus. 

 cylindricus, see Agraulus cylindricus. 

 oweni, see Crepicephalus oweni. 

 planus, see Agraulus planus. 

 pustulatus, see Agraulus pustulatus. 

 quadrangularis, see Agraulus quadrangu- 



laris. 



subclavatus, see Agraulus subclavatus. 

 texanus, see Agraulus texanus. 

 tripunctatus, see Agraulus tripunctatus. 

 ARISTOZOE, Barrande, 1872, Syst. Sil. Boh., 

 vol. 1, p. 477. [Ety. an'sios, best; zoon, 

 animal.] Carapace bivalve ; test thin; 

 hinge-line straight; ventral margin 

 grooved and reflected ; tubercle near 

 anterior margin. Type A. bisulcata. 

 rotundata, Walcott, 1887, Am. Jour. Sci. 

 and Arts, 3d ser., vol. 4, p. 193, Up. 

 Taconic. 



troyensis, Ford, 1873, (Leperditia troyen- 

 sis,) Am. Jour. Sci. and Arts, 3d ser., 

 vol. 6. p. 138, Up. Taconic. 

 ASAPHISCUS, Meek, 1873, 6th Rep. Hayden's 

 Geo. Sur. Terr., p. 485. [Ely. from the 

 genus Asnphus.] Distinguished from 

 Asapbus by having nine thoracic seg- 

 ments, a conical and well-defined gla- 

 bella, without lateral lobes, the furrow 

 at the anterior margin of the head, 

 and less arcuate eyes more remote 

 from the glabella ; distinguished from 

 Bathyurellus by 

 having its conical 

 glabelladepressed, 

 and the margin 

 of the head, in 

 front, first con- 

 vex, and eloping 

 forward into a 

 transverse mesial 

 furrow, and then 

 rising in a convex 

 margin ; the me- 

 sial lobe of the 

 pygidium is 

 longer, and the 

 free margins nar- 

 rower, less flat- 

 tened and alate. 

 Type A. wheeleri. 

 bradleyi, Meek, 1873, 6th Kep. Hayden's 

 Geo. Sur. Terr., p. 484, Up. Taconic. 



965. Asnpbiscus 

 wheeleri. 



wheeleri, Meek, 1873, 6th Rep. Hayden's 

 Geo. Sur. Terr., p. 485, and Geo. Sur. 

 W. 100th Mer., vol. 4, p. 43, Up. Ta- 

 conic. 



ASAPIIOIDICHNTJS, S. A. Mil- 

 ler, 1880, Jour. Cin. 

 Soc. Nat. Hist,, vol. 2, 

 p. 217. [Ely. Asaphus, 

 a genus ; eidos, form ; 

 ichnos, track.] A track 

 supposed to have been 

 made by a crustacean. 

 Type A. trifidus. 



dyeri, S. A. Miller, 1880, 

 Jour. Cin. Soc. Nat, 

 Hist, vol. 2, p. 219, 

 Utica Slate Gr. 



trifidus, S. A. Miller, 

 1880, Jour. Cin. Soc. 

 Nat. Hist., vol. 2, p. 

 218, Utica Slate Gr. 

 ASAPHUS, Brongniart, 1822, 

 Hist., Nat, Crust. Foss., 

 p. 17. [Ety. asaphus, un- 

 certain, obscure.] Body 

 somewhat elli p t i c a 1 , 

 sides straightened; 

 cephalic shield and 

 pygidium nearly equal 

 and somewhat semiel- 

 liptical; glabella con- 

 tracted between the 

 eyes; eyes large, 

 smooth ; facial sutures 

 extending forward and 

 outward in advance of 

 the eyes, and then curv- 

 ing to the middle of the 

 front margin, poste- 

 riorly extending ob- 

 liquely outward, and 

 cutting the posterior 

 margin of the cephalic 

 shield within the lat- 

 eral angles ; thoracic 

 segments 8, with wide, 

 nearly straight pleural 

 grooves; axis of pygid- 

 ium, when traceable, 

 elongate conic, seg- 

 ments usually indis- 

 tinct. Type A. cornig- Fio. 900. Asnph- 

 erng oidiclmus trifl- 



acantJioleurus, see D a 1 - 



manites acantholeurus. 

 alacer, Billings, 1866, Catal. Sil. Foss. 



Anlic., p. 26, Hud. Riv. Gr. 

 a'pectans, see Dalmanites aspectans. 

 attragaloUs, Green, 1834, Am. Jour. Sci., 



vol. 25, p. 325. Probably founded upon 



the pygidium of a Pbacops. 

 barrandi, Hall, 1851, Lake Sup. Land 



Dist., p. 210, Birdseye Gr. 

 canadensis, Chapman, 1856, Can. Jour. 



vol. 2, p. 47, Trenton Gr. 

 canalis, Conrad, 1847, Pal. N. Y., vol. 1, 



p. 25, Chazy Gr. 

 caribouen&is, Walcott, 1885, Monogr. U. S. 



Geo. Sur., vol. 8, p. 98, Quebec Gr. 



