CANANDAIGUA AND NAPLES QUADRANGLES 



63 



acutirostrum, Honeoyea desmata and B u c h i- 

 ola retrostriata, Palaeotrochus praecursor 

 and Bactrites. In certain layers fragments of plants abound, 

 chiefly of Lepidodendron. 



Grimes sandstone 



The Portage or Naples fauna has now disappeared except 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: 



Protonympba devonica Clarke 

 Palaeochaeta salicifolia Clarke 

 Conularia cf. continens Hall 

 Paracyclas sp. 



Graimnysia subarcuata Hall 

 Aviculopecten cf. cancellatus Hall 

 Sphenotus sp. 

 Orbiculoidea 



Scbizophoria impressa Hall 



Leptostropbia mucronata Vanuxem 

 Chonetes lepidus Hall 

 Liorbyncbus mesacostalis Hall 

 L. globuliformis Vanuxem 

 Productella lacbrymosa Hall 

 Anibocoelia unibonata Conrad 

 Atrypa spinosa Hall 

 Paropsonema cryptophyurn Clarke 

 bictyospongia baplea 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 Gramrnysia elliptica Hall 



Palaeotrochus praecursor Clarke Pboladella cf. parallela Hall 

 Aviculopecten cancellatus Hall Leptodesrna robustuin Hall 



