162 



STUDIES IN EVOLUTION 



Pterygometopus Schmidt. 156 



Ptychaspis Hall. 142 



Ptychometopus Schmidt. 154 



Ptychoparia Corda. 142 



Ptycliopyge Angelin. 146 



Raphiopliorus Angelin. 138 



JRemopleurides Portlock. 142 



Salteria Walcott. 140 



Salteria W. Thompson. 138 



Sao Barrande. 142 



jSchmidtella Tsehernyschew. 148 



Schmidtia Marcou. 142 



Selenopeltis Corda. 151 



Shumardia Billings. 133 



Solenopleura Angelin. 142 



Sphcerexochus Beyrich. 155 



Sphmrocoryphe Angelin. 155 



Sphoeropthalmus Angelin. 142 



Staurocephalus Barrande. 155 



Page 



Stygina Salter. 146 



Symphoria Clarke. 156 



Symphysurus Goldfuss. 146 



Telephus Barrande. 142 



Terataspis Hall. 150 



Thafeops Conrad. 146 



Toxotis Wallerius. 140 



Triarthrella Hall. 142 



Triarthrus Green. 142 



Trimerocephalus McCoy. 156 



Trimems Green. 154 



Trinudeus Lhwyd. 138 



Triopus Barrande. 133 



Trochurus Beyrich. 150 



Tropiidocorypihe Novak. 148 



Uraliclias Delgado. 150 



Xiphogomium Corda. 148 



Youngia Lindstrom. 155 



Zacanthoides Walcott. 142 



