UPPER LIMIT OF THE CLINTON 353 



in common with the Waldron shale as with the Osgood beds, and espe- 

 cially such index species as Clorinda fornicata, Camarotoechia acinus, 

 Brachyprion profundum, and Whitfieldella nitida. Consequently we may, 

 perhaps, have to approximate the Waldron and Laurel more closely to the 

 Irondequoit and the Osgood to the Brewerton when we know these New 

 York faunas better. 



LAKEPORT LIMESTONE 



Immediately below the typical fossiliferous Eochester shale and above 

 the Donnelly ore in the Lakeport hole there are 16 feet of ^^limestone 

 with considerable shale'^ (9 : 38) that have been interpreted by Hartnagel 

 (9:25) as summit Clinton. Corresponding to these in position in the 

 South Granby well, the next hole west to penetrate this horizon, are but 

 18 inches of "impure limestone with fossils" "grading apparently into 

 the" Rochester (9: 3G, 24). Without knowledge of their fauna the im- 

 portance of these beds can not well be evaluated, so it will be safer to 

 employ temporarily a local designation for them. The underlying Don- 

 nelly ore crops out at Joscelin's Corners (1 : 89; 9 : 26) and elsewhere in 

 the vicinity of Lakeport, and must expose some portion of this limestone 

 along with it. 



Conditionally we may follow HartnagePs apprehension of the mass as 

 summit Clinton, but whether uppermost Irondequoit coordinate with the 

 "reef" zone at Rochester or a new intercalated member is as uncertain as 

 the third possibility — that it is a calcareous eastern facies of the lower 

 true Rochester (above the "reef" horizon). The last suggestion gathers 

 force from the fact that, contrary to the Clinton rule, the Rochester shale 

 grows more calcareous in passing eastward from ]N"iagara to Rochester — a 

 tendency that may still prevail toward the east, where its outcrop is under 

 the drift. 



Upper Limit of the Clinton 



The higher beds at Clinton contain small faunas consisting largely of 

 Rochester shale species, from which it has been argued that the Rochester 

 horizon is itself present in the type Clinton section. But the drillings 

 show that these beds lie below the Rochester around Oneida Lake, with 

 the Lakeport (upper Irondequoit) limestone and Donnelly ore interven- 

 ing. The Rochester shale, which is at least 75 feet thick at Wolcott^^ 

 (Hall thought it nearly 100 ; 2 : 97), has thinned to 29 feet at Lakeport, 

 though still quite recognizable, and is wholly unknown east of this well. 

 The only apparent bond between this dwindling shale and the 70-foot 



w Including probably the division presently to be distinguished as the Gates. 



