262 CALIFORNIA ACADEMY OF SCIENCES. 



ACIDASPIS. AGNOSTUS. 



TUBERCULATus Hall, 1859; Pal. New York, vol. 3, p. 3G8, pi. 79, figs. 



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



TUBERCULATU.s Hall, 1861; loth Eep. New York State Cab. Nat. His., 



pi. 2, fig. 3. 

 Ceratocephala (Acidaspis) tubercclatus Clarke, 1892. Note on Aci- 

 dasjns, p. 13. 

 AC4LASPIS Hall, 1862; Canadian Naturalist, vol. 7, p. 445, figure. Hall, 

 1863; 16th Eep. New York State Cab. Nat. Hist., p. 181. 



BARRANDi Hall, 1863; 16th Rep. New York State Cab. Nat Hist., p. 



181, pi. 11, tigs. 7-16. Miuiska, Minn., and Mazomania, Wis. 



Taconic. 



EATONi Whit., 1880; Ann. Eep. Geol. Survey, Wisconsin, \). 52. 



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



Lodi, Wis. Taconic. 



Arctinurun De Castelnau, 1843; Sil. Syst. de TAmrrique, p. 21. (See 



Lichas holtoni.) 

 Agnostus Broug., 1822; Hist. Nat. Crust. Foss., p. 38. Taconic. Cambrian. 

 Syn., Battus Dalm., 1826; Pala^ad., p. 33. 



Trinodus M-cGoy, 1846; Sil. Foss. Ireland, p. oQ. 

 Phalacroma Cord, (in i^art), 1847; Prodr., p. 158. 

 Mesospheniscus ComA., 1847; Prodr., -p. AQ [Agnostus integer). 

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

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

 Lcjopyge Cord., 1847; Prodr., p. 51 (Agnostus Icevigatus). 

 ArthrorhacMs Cord., 1847; Prodr., p. 114 [Agnostus tardus). 

 Peronopsis Cord., 1847; Prodr., p. 115 (Agnostus integer). 

 Pletiroctenhwi Cord., 1847; Prodr., p. 116 (Agnostus granulatus). 

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



section. Type 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 pj^gidium 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. p)isiform}s 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 i^ygidium 

 is usually proditced into lateral spines. Type Agnostus rexHavv. 

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

 and side lobes of the pj'gidium. Both the anterior lobe of the 

 glabella and the posterior lobe of the pygidium expand. Tj'pe 

 Agnostus rex Barr. 



