262 CALIFORNIA ACADEMY OF SCIENCES. 



ACIDASPIS. AGNOSTUS. 



TUBERCULATUs Hall, 1859; Pal. New York, vol. 3, p. 368, pi. 79, figs. 



1-14. Albany and Schohaine counties, N. Y. 



TUBKROULATUS Hall, 1861; 15th Rep. New York State Cab. Nat. His., 



pi. 2, fig. 3. 

 Ceratocephala {Acidai^pix) tuberculatus Clarke, 1892. Note on Aci- 

 ilaspis, p. 13. 

 AoLASPis Hall, 1862; Canadian Naturalist, vol. 7, p. -145, figure. Hall, 

 1863; lethEep. New York State Cab. Nat. Hist., p. 181. 



BARRAXDi Hall, 1863; 16th Eep. New York State Cab. Nat Hist., p. 



181, pi. 11, figs. 7-16. Miniska, Minn., and Mazomania, Wis. 



Tacouic. 



EATONi Whit., 1880; Ann. Rep. Geol. Survey, Wisconsin, p. 52. 



EATONI Whit., 1882; Geol. Wisconsin, vol. 4, p. 192, pi. 10, fig. 11. 



Lodi, Wis. Taconic. 



Arrlinurm De Casteluau, 1843; Sil. Syst. de rAnn'rique, p. 21. (See 



Lichas hoUoiii.) 

 A(iNOSTUS Brong., 1822; Hist. Nat. Crust. Foss., \). 38. Tarouii;. Ciuiibrian. 

 Syn., Battm Dalm., 1826; Palii?ad., p. 33. 



Trinodus McCoy, 1846; Sil. Foss. Ireland, p. 56. 

 Phalacroma Cord, (in part), 1847; Prodr., p. 158. 

 Mesospheniscus Cord., 1847; Prodr., p. 46 {Agiiostus integer). 

 Diplorrhina Cord., 1847; Prodr., p. 46. 

 Condylopyge Cord., 1847; Prodr., p. 50 (Agnostus rex). 

 Lejopyge Cord., 1847; Prodr., p. 51 (Agnosius lievigattcs). 

 A rthrorhachin Cord., 1847; Prodr., p. 114 (Agnostus tardus). 

 Peronops'iH Cord., 1847; Prodr., p. 115 (Agnostns integer). 

 Pleurocienium Cord., 1847; Prodr., p. 116 (Agnosius granulatim). 

 Sec. 1. Parvifroxtes. The glabella is only partly developed in this 



section. Tj'pe Agnostus brevifrons Ang. 

 Sec. II. Longifrontes. This section is distinguished by its strongly 

 projecting glabella and also by the axis of the pygidium, which is 

 generally moderately long. Crust smooth. The cheeks grooved. 

 The crust on the cheeks and pygidiiim is provided with raised 

 points. Limb generally narrow. The cheeks in front of the glabella 

 and side lobes of the pygidium, behind the axis, divided by a 

 groove. Type Agnostus punctuosus Aug., A. pisi/onnis Linne. 

 Sec. III. LiMBATi. General form subquadrate, head has a broad limb, 

 basal lobes large. The cheeks in front of the glabella are not 

 divided by a central groove or grooved at the sides. The pygidium 

 is usually produced into lateral spines. Tj-pe Agnostus rexBarr. 

 Series A (Regii). Distinguished by its broad limb, diminishing cheeks 

 and side lobes of the pygidium. Both the anterior lobe of the 

 glabella and the posterior lobe of the pygidium expand. Type 

 Agiiostus rex Barr. 



