FAUNAS OF DEVONIAN SECTION NEAR ALTOONA 633 



to be in the New York sections.^ Martinia suhumhona has been 

 observed at only one locahty, several miles to the southwest of Altoona. 

 It occurs abundantly in an outcrop in the wagon road about i mile 

 northeast of Queen. 



The Hamilton appears to be generally less richly fossiliferous 

 than it is in the central New York sections. 



Genesee jauna. — The Tully limestone is absent from the section 

 and the dark sandy shales of the Hamilton are followed by the fissile 

 black shale of the Genesee. The Genesee shale of this section is 

 identical in lithologic features with the Genesee of the Finger Lake 

 region. Like the Genesee of the Cayuga Lake section, fossils are 

 very scarce in it. Only two species have been observed. These are : 

 Styliolina fissurella Sandbergeroceras sp. undt. 



Nunda jauna. — The Genesee is succeeded by the grayish sandy 

 shales and flags of the Nunda. The fauna which this series of beds 

 has aiforded comprises the following species: 



Cladochonus sp. Buchiola reiriosiriata 



Palaeon'eilo petila Ontaria cj. accinta 



Pterochaenia jragilis Phragmosoma natator 



Pterochaenia cashaquae Probeloceras lutheri 



Paracardium doris Styliolina fissurella 



Paracardium delicatulum Coleolus aciculum 



This fauna is typical of the Nunda of western New York. All of 

 the species in it are found in the western New York fauna, while 

 none of the forms characteristic of the Ithaca fades occur in it. 



During the interval represented by the shales and sandstones of 

 the Nunda two marine faunas, entirely distinct in origin and com- 

 position, occupied that portion of the Devonian sea which extended 

 over the present area of central and western New York, central 

 Pennsylvania, and western Maryland. The habitat of these faunas 

 extends southward into Virginia and West Virginia to a point not 

 yet determined. In New York, where these contemporary faunas 

 have been very thoroughly studied, one of them, usually called the 

 Ithaca fauna, is found occupying an area lying in general to the 

 eastward of that held by the other. The eastern fanua was the in- 

 shore fauna while the western facies was the more pelagic and proba- 



I Sixteenth Annual Report, State Geologist of New York, 1898, p. 273; Bulletin 

 No. 206, U. S. Geological Survey, p. 47. 



