CANANDAIGUA AND NAPLES QUADRANGLES 



63 



acutirostmm, Honeoyea desmata and B u c h i- 

 ola retrostriata, PalaeatrocJius praecursor 

 and Bactrites. In certain layers fragments of plants abound, 

 chiefly of Lepidodendron. 



Grimes sandstone 



The Portage or Naples fauna has now disappeared jexcept for 

 a few straggling and modified representatives in the higher rocks 

 and with the Grimes sandstone appears a well defined though 

 somewhat sparse brachiopod fauna. We originally regarded 

 this small fauna of the Grimes sandstone as a representative of 

 the Chemung fauna but have subsequently expressed the view 

 that it is rather the invading Ithaca fauna from the east. The 

 distinction is a refined one; it would be extremely difficult to 

 indicate at what time or horizon in the succession the term Che- 

 mung is to be applied to the homogeneous fauna occupying the 

 field of central New York during the upper Devonic. 



The fauna of the Grimes sandstone is as follows : 



Protonympha devonica Clarke 



Palaeocliaeta salicifolia Clarke 



Conularia cf. continens Hall 



Paracyclas sp. 



Grammysia subarcuata Hall 



Aviculopecten cf. cancellatus Hall 



Sphenotus sp. 



Orbiculoidea 



Schizophoria impressa Hall 



Leptostrophia mucronata Vanuxem 

 Clionetes lepidus Hall 

 Liorhynchus mesacostalis Hall 

 L, globuliformis Vanuxem 

 Productella lachrymosa Hall 

 Ambocoelia umbonata Conrad 

 Atrypa spinosa Hall 

 Paropsonema cryptophyum Clarke 

 Dictyospongia haplea Hall & Clarke 



West Hill flags and sandstone 



The fauna of these beds is a continuation of the brachiopod 

 fauna of the Grimes sandstone with some interesting additions. 

 Nowhere are the fossils abundant and none are specially dis- 

 tinctive of the Chemung fauna so that we may regard these beds 

 also as a continuation of the Ithaca invasion from the east. 

 The fossils recorded are as follows: 



Manticoceras oxy Clarke 

 Palaeotrochus praecursor Clarke 

 Aviculopecten cancellatus Hall 



Graniniysia elliptica Hall 

 Pholadella cf. parallela Hall 

 Leptodesma robustum Hall 



