50 NEW YORK STATE MUSEUM I 



i 



probably has suffered a longer erosion and may for that reason i 

 be now much reduced in thickness. ' 



The fauna of these shales on the two quadrangles is small but 

 present in all outcrops and characteristic of the formation. It con- 

 sists of the graptolites : 



Corynoides calicularis Nicholson 

 Dicranograptus nicholsoni Hopkinson 

 Diplograptus amplexicaulis Hall 

 D. (Mesograptus) putillus Hall 

 D. (Mesograptus) mohawkensis Rued. 

 Climacograptus spiniferus Rued. 

 Glossograptus quadrimucronatus mut. cornutus Rued, and 1 

 other mutations ; 



Lasiograptus eucharis (Hall) I j 



li 



Besides these there are met with worms (Eopolych actus i 



albaniensis and Pontobdellopsis com eta) described ! 

 from this formation by the writer in Bulletin 42 (1901) and small 



brachiopods (Leptobolus insignis Hall, S c h i z o - ! 



crania filosa Hall) and a few cephalopods ( T r o c ho 1 i t e s | 



ammonius Conrad, Orthoceras arcuolineatum Rued., j 



O.hudsonicum Rued. ) and rarely a head ofaTriarthrus ! 



becki. Of these are common only Corynoides calicu- \ 



laris, Climacograptus spiniferus, Diplograptus ' 

 amplexicaulis, putillus , mohawkensis and 



Lasiograptus eucharis. Dicranograptus nich- | 



o 1 s o n i , so common in the Snake Hill beds, is very rare, while : 



Lasiograptus eucharis is present in every outcrop ; the , 



other graptolites here cited are not always associated but rather | 



distributed in subzones of the formation not yet distinguished. ; 



Thus in Ballston Spa the beds exposed in the village are full of , 



Climacograptus spiniferus and Diplograptus I 



amplexicaulis, but going up the Kayaderosseras creek one \ 



first meets thick-bedded mud shales and above these G 1 o s s o - j 



graptus quadrimucronatus mut. and Lasiograptus , 



eucharis have become the dominant forms. The outcrop a1 | 



the Carlsbad Spring near Saratoga contains : I 



i 



Diplograptus (Mesograptus) mohawkensis "\ 



Climacograptus spiniferus, and ': 



Lasiograptus eucharis M t 



