INTRODUCTION. 



XVI 1 



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 thai 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 : 



TR1LOBITA: 



'i/inrne platys. 



Phacops cristata. 



Phacops cristata, var. pipa. 

 [?] Phacops rana. 



Dalmaniles ill <tyx. 



Dalmanites (Hausinannia 



Dalmanites (Haul ius, var. serritla. 



Da 3 '") phacoptyx. 



ra) aspectans. 



ecophorUS. 

 • 

 [>] Dalm ■ Boullii. 



Dolman': rus. 



Dalmanites | Odontocephahis) bifidus. 



Dal tocephalus) jSOgeria. 



Dalmaii ites (Odontoet / tJtalus) con mat its. 



Dalmanites (Cory cepht 



Dalmanites (Ohasmops) anchiops. 



Dalmanites (Ohasmops) a par. armatus. 



Dalmanites (Chasmops) Calypso. 



Dalmanites (Chasmops?) Erina. 



Da macrops. 



Acidaspis eallicera. 



Acidaspis sp. 



LicJtas ('/■' rataspis) grandis. 



!,',• lias | 1 'ova "" has) ! ispidus. 



Lichas (Conolichas) Eriopis. 



T1UL0BITA : 



Lichas (Hbpl i a as. 



Lichas (Arges) eontusus. 



Li i ' > as) gryps. 



Lichas i ( 



Proei 



Proetvs follicep 



Pii itus clarus. 



Pi i US. 



Pn<t V( 



Pi < 'lige- 



Proitus omfro 

 Proitus ddphin 

 Proetus (?) pla 

 Proitus tti in id us. 

 Phailho.ii 



Phaethonides varicella. 

 Phaethonides <jt tmna us. 

 Cyphaspis mi 

 Cyphaspis 



Cyphaspis hybr 



CIRRIPEDIA : 



Pui' uca. 



osus. 

 Tar, Hi pax canceUatus. 



