526 



CRUSTACEA. 



[ACI. AGN. 



PIG. 951. Acidaspis 

 anchoralis. Cephal- 

 ic shield. 



insequalis, Meek & Worthen, syn. for Pal- 



aeocaris typus. 



stimpsoni, Meek & Worthen, 1865, Proc. 

 Acad. Nat. Sci., p. 47, and Geo. Sur. 

 111., vol. 2, p. 401, Low. Coal Meas. 

 ACIDASPIS, Murchison, 1839, Sil. Syst., p. 

 658. [Ety. akis, a point ; ospis, shield.] 

 Cephalic shield, semicircular, margin 

 thickened and spinous, lateral angles 

 produced in spines; glabella convex, 

 narrow in front, not reaching the mar- 

 gin, two lobes on each side, and having 

 a large spine projecting backward, eyes 

 prominent; thorax with eight seg- 

 ments; pleurae wide, and terminating 

 in spines; pygidium small, axis short, 

 of two joints, sides depressed, one seg- 

 mental furrow, long spine extending 

 backward from the margin at each side, 

 and smaller spines from the other parts 

 of the margin. Type A. brighti. 



anchoralis, S. A. Mil- 

 ler, 1875, Cin. Quar. 

 Jour. Sci., vol. 2, p. 

 349, Hud. Riv. Gr. 

 callicera. Hall, 1888, 

 Pal. N.Y., vol. 7, 

 p. 69, Up. Held. Gr! 

 ceralepta, Anthony, 

 1838, (Ceratoceph- 

 ala ceralepta,) Am. 

 Jour. Sci., vol. 34, p. 379. Not defined 

 so as to be recognized, 

 cincinnatiensis, Meek, 1873, Ohio Pal., 



vol. 1, p. 167, Hud. Riv. Gr. 

 crosotus, Locke, 1843, 

 Am. Jour. Sci., vol. 44, 

 p. 347, and Ohio Pal., 

 vol. 1, p. 165, Hud. Riv. 

 Gr. The word is mis- 

 spelled; it should be FIG. 952. Acidas- 

 crossota. pis anchoralis. 



danai, Hall, 1862, Geo. Podium. 



Sur. Wis., p. 423, Niagara Gr. 

 eriopis, see Terataspis eriopis. 

 fimbriata, Hall, 1879, Desc. New Spec. 

 Foss.. p. 20, and llth Rep. Geo. and 

 Nat. Hist. Ind., p. 334, Niagara Gr. 

 grandis, see Terataspis grandis. 

 halli, Shumard, 1855, Geo. Sur. Mo., p. 



200, Trenton Gr. 



hamata, Conrad, 1841, (Dicranurus ha- 



matus,) Ann. Rep. N. Y., p. 48, and 



Pal. N. Y., vol. 3, p. 371, Low. Held. Gr. 



horani, Billings, 1859, Rep. of Progr. Geo. 



Sur. Can., p. 341, Trenton Gr. 

 ida. svn. for Acidaspis danai. 



onealli, S. A. Miller, 1875, 

 Cin. Quar. Jour. Sci., vol. 

 2, p. 86, Hud. Riv. Gr. 

 parvula, Walcott, 1877, 31st 

 Rep. N. Y. St. Mus. Nat. 

 Hist., p. 69, Trenton Gr. 

 romingeri, Hall, 1888, Pal. N. 

 Y'> v l' ^' P' ^i Ham. Gr. 

 spiniyer, see Bathyurus 



spiniger. 



trentonensis, Hall, 1847, Pal. N. Y., vol. 1, 

 p. 240, Trenton Gr. 



tuberculata, Conrad, 18-10, Ann. Rep. 

 N. Y., p. 205, and Pal. N. Y., vol. 3. p. 

 368, Low. Held. Gr. 



AGLASPIS. Hall, 1862, Can. Nat. and Geo., 

 vol. 7, p. 443, and 16th Rep. N. Y. St. 

 Mus. Nat. Hist., p. 181. [Ety. aglaos, 

 bright; aspis, shit-Id.] Cephalic shield 

 somewhat semielliptical, wider than 

 long, sinus in front ; glabella narrow, 

 conical; eyes prominent, and situate 

 anterior to the middle; thorax having 

 eight segments; pygidium small, and 

 terminating in a single spine. Type A. 

 barrandii. 



barrandii, Hall, 1862, Can. Nat. and Geo., 

 vol. 7, p. 443, and 16th Rep. N. Y. St. 

 Mus. Nat. Hist., p. 181, Potsdam Gr. 



eatoni, AVhil field, 1880, Ann. Rep. Geo. 

 Sur. Wis., p. 52, and Geo. of AVis., vol. 

 4, p. 192, Potsdam Gr. 



AGNOSTUS, Brongniart, 1822, Hist. Nat. 

 Crust. Foss., p. 38. [Ety. agnostos, ob- 

 scure.] Body elongate, elliptical ; ce- 

 phalic shield and pygidium subequal, 

 subrotund, or longer than wide, convex 

 rim on the border; glabella convex; 

 no eyes; no facial sutures; two thoracic 

 segments. Type A. pisiformif. 



acadicus, Hartt, 1868, Acad. Geol., p. 655, 

 St. John Gr. 



acadicus var. declivis, Matthew, 1885, 

 Trans. Roy. Soc. Can., p. 70, St. John Gr. 



acutilobus, Matthew, 1885, Trans. Roy. 

 Soc. Can., p. 73, St. John Gr. 



arnericanus, Billings, 1860, Can. Nat. and 

 Geol., vol. 5, p. 301, and Pal. Foss, p. 

 395, Up. Taconic. 



bidens, Meek, 1873, 6th Rpp. Hayden's 

 Geo. Sur. Terr., p. 463, and Monog. U. S. 

 Geo. Sur., vol. 8, p. 26, Prospect Mount- 

 ain Gr., Up. Taconic. 



canadensis, Billings, 1860, Can. Nat. and 

 Geol., vol. 5. p. 301, and Pal. Foss., vol. 

 1, p. 397, Up. Taconic. 



coloradoensis, Shumard, 1861, Am. Jour, 

 Sci. and Arts, 2d ser., vol. 32, p. 218, 

 Up. Taconic. 



communis, Hall & Whitfield, 1877, U. 8. 

 Geo. Expl. 40th parallel, vol. 4, p. 

 288, Prospect Mountain Gr., Up. Ta- 

 conic. 



?disparilis, Hall, 1863, 16th Rep. N. Y. 

 St. Mus. Nat. Hist., p. 179, Potsdam Gr. 



fabius, Billings, 1865, Pal. Foss., vol. 1, p. 

 298, Up. Taconic. 



galba, Billings, 1865, Pal. Foss., vol. 1, p. 

 297, Up. Taconic. 



interstrictus, White, 1874, Rep. Invert. 

 Foss., p. 7, and Geo. Sur. W. 100th 

 Mer., vol. 4, p. 38, Up. Taconic. 



? josepha, Hall, 1863, 16th Rep. N. Y., St. 

 Mus. Nat. Hist., p. 178, Potsdam Gr. 



latus, see Beyrichia lata. 



lobatus, see Microdiscus lobatus. 



maladensis, Meek, 1873, Hoyden's Sur. 

 Terr., p. 464. Not properly d' fined. 



neon, Hall & Whitfirld, 1877, U. S. Geo. 

 Expl., 4th parallel, vol. 4, p. 229, Pros- 

 pect Mountain Gr., Up. Taconic. 



