3/4 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Fossils typical. — Fucoides verticalis ; Atrypa elongata ; A. peculiaris ; 

 Chonetes complanata; Leptaena depressa, var. ventricosa, and L. nucleata 

 (Hall); Orthis unguiformis ; O. musculosa; six RhynchoDellae ; Spirifer 

 macropterus ; Acroculia crassifrons. 



Fossils occurrent in Europe. — Stromatopora concentrica ; Cyathocri- 

 nites pyriformis (W.); Atrypa unguiformis; Spirifer arenosus; S. cultri- 

 jugatus? (Devon.); S. macropterus (Devon.); S. Urii (Devon.); Atrypa 

 reticularis. 



Fossils recurrent in New York. — These are eleven in number, most 

 of them being Brachiopoda, and some from all the three stages of 

 the Silurian system, on their way into still higher Devonian strata. 



Caudagalli Grit. 



Mineral Character. — This is an argillo-calcareous sandstone, pass- 

 ing into green shale. It is merely an upper portion of the Oriskany 

 sandstone. 



Transition. — In the State of New York, Vanuxem (p. 129) saw it 

 resting upon the Delthyris shaly limestone, in one of the frequent 

 absences of Oriskany Sandstone proper. 



Place. — It generally accompanies Oriskany Sandstone. It extends 

 from the western frontier-line of Schoharie County, eastwards by 

 Schoharie, to the eastern brow of the Helderberg Mountains. From 

 thence its outcrop goes south-east and south to Kingston. It is not 

 seen in the Mamakating Valley further south-west than Marbletown. 



This stratum has not been seen in Central New York, westwards, 

 beyond Herkimer County, and not at all in Western New York. It is 

 first visible eastwards in Mather's (S.E.) district, on the north side 

 of Cherry Valley village, some miles from its last western appearance. 



Position. — Is conformable to the groups adjacent. 



Thickness. — Mather (Rep. p. 341) states this to be about fifty feet. 



Fossils. — It presents only one — the elegant fucoid like a cock's 

 tail, which also occurs in the Hamilton and Chemung groups. 



Schoharie Grit. 



Mineral Character. — This is a calcareous, fine-grained sandstone, 

 — the carbonate of lime disappearing on exposure to weather, without 

 alteration in the form of the rock. 



Transition. — This rock and the last described are so thin, that, 

 in De Verneuil's opinion, and in that of most geologists, they ought 

 to be united. 



Place. — Schoharie grit is local, and does not extend far west from 

 Schoharie. By Mather it has only been seen near Schoharie and 

 Clark ville, in South-eastern New York. Vanuxem states that this 

 stratum does not exist in Central New York. 



Thickness. — Only eight or ten feet at Schoharie. 



Position. — This is the same as in the neighbouring strata. 



Fossils. — This rock is marked as the lowest point at which in 

 New York we recognize the type of Devonian fish, J. Gebhard having 

 found in it a fragment of the Asterolepis (Verneuil, Bull. S. G. Fr. 

 2 ser. iv. p. 658). 



