PART II 



CATALOGUE OF TRILOBITES. 



For the geological horizons the author has used the 

 term "Cambrian" for the original Cambrian of Sedg- 

 wick, 1836 (Lower Silurian, Murchison). The term 

 " Taconic " is used for the zone with the Olenellus, Par- 

 adoxides, Olenus and Dicellocephalus faunae. " Silurian" 

 is used for Murchison's Upper Silurian. 



A SYSTEMATIC CLASSIFICATION OF THE GENERA. 



AcXOSTIDiE. 



Agnoshis Bronguiart, 1822. Hist. Crust. Foss., p. 38. Type, Agnostus 

 pisiformis Liunt-. Taconic. Cambrian. 



Sec. 1. Parvifrontes. Tj'pe, Agnostus hrevifrons Ang. 

 Sec. 2. Lougifrontes. Type, A. j3U7ictuosus Ang. 

 Sec. 3. Limbati. Type, A. rex Barr. 



(B) Fallaces. Tyi^e, A. fallax Tiiurs. 

 Sec. 4. Lffivigati. Type, A. IcBvigatus Dalia. 

 Sec. 5. Arthrorhachis. Type, A. tardus Bavi'. 

 Shumardia Billings, 1862. Pal. Foss., vol. 1, p. 92. Type, Shumardia 

 granulosa Bill. Taconic. 



Microdiscus Emmons, 1856. Am. Geology, vol. 1, pt. 2, p. 116. Type, 

 M. speciosus Ford. Taconic. 



Trinucleid;e. 

 Triniicleus Lhhvyd, 1698 (Cryptolithns Green, 1832). Murchisou's Silu- 

 rian Syst., 1839, p. 659. Type, Trinucleusjimhrlalus Mnrcb. 



Cambrian . 

 .\mpyx Dalman, 1826. Pabead., p. 53. Type, Ampyx nasut^is Dalm. 



Cambrian. Silurian. 

 Sec. 1. Brevifrontes. Type, Ampyx nndus'Mwvch . 

 Sec. 2. Longifrontes. Type, A. nasutus Dalm. 

 Sec. 3. Louchodomas. Type, L. domaius Ang. 

 Dionidffi Barraude, 1847. Nei;es Jahrb. ftir Mineral., 1847, pt. 4, p. 391; 

 Syst. Sil. Bolieme, vol. 1, p. 540. Type, Dionidce formosa Barr. 



Cambrian. 



1. Salteria Wyv. Tliompson, 1864. Mem. Geol. Survey United King- 

 dom, decade xi, ill. 7, p. 1. Type, Salteria primieva Wyv. Thorn. 



2. Endyminia Billings, 1862. Pal. Foss., vol. 1, p. 93. Type, En- 

 d]iminia mecki Bill. Cambrian. 



