66 



NEW YORK STATE MUSEUM 



Orbiculoidea schucherti 



Pholidops cf. ovata 



P. terminalis 



Craniella (?) grandegrevensis 



Chonetes canadensis 



C. antiopa 



Hipparionyx proximus 



Stropheodonta lincklaeni 



S. magniventer 



Leptostrophia magnifica (tullia) 



Leptaena rhomboidalis 



Spirifer arenosus 



S. cyclopterus 



S. murchisoni 



S. plicatus 



Cyrtina rostrata 



Meristella lata 



Leptocoelia flabellites 



Megalanteris plicata 



Beachia amplexa 



Rensselaeria ovoides gaspensis 



Thirty-one in all, a very large proportion of the Perce fauna itself 

 but a small one of the entire Grande Greve fauna. There are some 

 noteworthy differences in development at the two places. Thus, the 

 most frequent species at Perce common to both localities, may be stated 

 in order of abundance 



Chonetes canadensis 

 Spirifer plicatus 

 Leptocoelia flabellites 



Leptostrophia magnifica (tullia) 

 Spirifer arenosus 

 Chonetes antiopa 



All of these are relatively rare on the Forillon. Eatonia is absent 

 at Perce and Proetus phocion, common at Grande Greve, is rare 

 here. Among the most abundant of all the species of the Perce rock is the 

 trilobite Probolium biardi, not known on the Forillon. 



The Perce massive thus represents some part of the Grande Greve 

 series as is evident from its fauna, but there is no evidence that it is any 

 part of the limestones now presented on the Forillon nor does it appear from 

 the fauna what position the massive holds with reference to the Grande 

 Greve series. The peculiar colors of the Perce strata are entirely wanting 

 on the rocks of the Forillon but these are as we have suggested a secondary 

 effect due to exposure. The Perce massive unlike the Forillon limestones 

 presents none of the lithic characters so peculiarly suggestive of the Onon- 

 daga beds of New York, the chert beds and the chocolate limestones. 

 There is an absence from the fauna of any species that suggest this later 

 s^ge, e. g., Stropheodonta patersoni precedens, S. parva 

 avita, S. crebristriata simplex, Strophonella continens 



