INTRODUCTION. 
xvii 
condition of preservation of the fossils is often unsatisfactory, the specimens 
being generally in a disjointed or fragmentary condition; moreover the char¬ 
acter of the matrix is such that it is often a matter of great difficulty to prepare 
the specimens in a proper manner for study. When the test of the animal has 
been silicified the matrix is usually in the same condition, and when preserved 
in the limestone, the substance of the test is usually softer and more friable*than 
the matrix. The transported boulders of chert which are found abundantly in 
the drift accumulations south of the lines of outcrop of these rocks, and have 
become decomposed by the gradual removal of the calcic carbonate mixed with 
the silica, have proven a very fruitful source of instructive specimens. On 
account of the usually fragmentary condition of the specimens, a few of the 
species here described may eventually prove to be founded upon different parts 
of similar animals. The following fifty-two species at present constitute the 
Crustacean fauna of this formation ; 
TMILOBITA: 
Calymene platys. 
Phaeops cristata. 
Phacops cristata, var. pipa. 
[?J Phacops rana. 
Dalmanites (Hausmannia) pleuroptyx. 
Dahmnites ^Hausmannia) concinnus. 
Dalmanites (Haus^nannia) concinnus, var. serrula. 
Dalmanites {Hausmannia) pihacoptyx. 
Dalmanites (Coronura) aspecta.ns. 
Dalmanites {Coromcra) myrmecophorus. 
Dalmanites {Cryphwus) comis. 
[?] Dalmanites (Oryphceus) Boothi. 
Dalmanites (Odontocephalus) selenurus. 
Dalmanites (Odontocephalus) bifidus. 
Dalmanites ( Odontocephalus) JEgeria. 
Dalmanites {Odontocephalus) ccrronaUis. 
Dalmanites {Corycephalus) pygmmus. 
Dalmanites {Chasmops) anchiops. 
Dalmanites {Chasmops) anchiops, var. armatus. 
Dalmanites {Chasmops) Calypso. 
Dalmanites {Chasmops?) Erina. 
Dalmanites {Chasmopsi macrops. 
Acidaspis callicera. 
Acidaspis sp. 
Lichas {Terataspis) grandis. 
Lichas {Conolichas) hispidus. 
Lichas {Conolichas) Ei'iopis. 
TRILOBITA: 
Lichas {Hoplolichas) hylwus. 
Lichas {Arges) contusus. 
Lichas {Ceratolichas) gryp)s. 
Lichas (Cemtolichas) dracon. 
Proehos crassimargbiatus. 
Proetus follicejxs. 
Proetus clarus. 
Proetus caiialiculatus. 
Proetus Verneuili. 
Proetus microgemma. 
Proetus stenopyge. 
Proetus ovifrons. 
Proetus delphinulus. 
Proetus {?) planimarginatus. 
Proetus Uimidus. 
Phaethonides arenicolus. 
Phaethonides varicella. 
Phaethonides gemmceus. 
Cyphaspis minuscxila. 
Cyphaspis stephanophora. 
Cyphaspis diadema. 
Cyphaspis hyhrida. 
CIRRIPEDIA: 
Palarocfreusia Devonica. 
Turrilepas flexuosus. 
Turrilepas cancellatus. 
