ORISKANY FAUNA OF BECRAFT MOUNTAIN 75 



Oriskania sinuata Orthothetes becraftensis 



Megalanteris ovalis O. large sp. n. 



Caniarotoechia oblata' Brachy prion schuchertanum 



C. pliopleura Hipparionyx proximus 



Leptocoslia flabellites Chonetes hudsonica 



Coelospira dichotoma Edriocrinus sacculus 

 Meri&tella lata 



This association has some peculiarities, e.g. the presence of some 

 of the Cumberland Md., species which have not before been observed 

 in the Oriskany of New York (P 1 a t y c e r a s g e b h a r d i and P . 

 reflexu m) and several forms of novel aspect. 



Orange county. In the southern extension of these beds a similar 

 fauna accompanies the calcareous strata. In Orange county true silicious 

 sandstones are absent but the pebble beds and cherts are well defined. 

 These features have been clearly brought out by the work of Dr 

 Heinrich Ries in his special report on the geology of this county, 

 published in the 15th animal report of the New York state geologist, 

 1898, p. 402, 433, etc. He says: 



The two belts of Oriskany which occur in this county present 

 widely different characters. The western belt forms the western part 

 of the Helderberg ridge, which extends up the Neversink valley from 

 Port Jervis. It consists of fine-grained, shaly sandstones and impure 

 limestones, the latter often containing many fossils. The limestones 

 weather to a soft, red rock, from which the fossils may often be dug 

 with a knife. The beds dip to the westward under the Esopus slates 

 and Pleistocene deposits of the Neversink valley, but the bedding is 

 almost everywhere obscured and there is present a pronounced cleavage 

 which causes the rock to split into very thin layers. The cleavage 

 generally dips steeply to the east. There are also present cherty bands 

 containing fossils. The Oriskany forms narrow ridges and the thick- 

 ness of the formation is about 125 feet [in the vicinity of Port Jervis]. 



The second Oriskany area is along the western side of Bell vale 

 and Skunnemunk mountains, where it affords a fine-grained red or gray 

 (juartzite which changes locally into a conglomerate. 



Fossils occur very sparingly In the silicious beds of the western 

 area, Ries recording there Anoplia nucleata, Leptocoelia 

 flabellites and Leptaena rh ombo idal i s . But on the west 



