123 Cincinnati Society of Natural History 



In the quarry within the northern Hmits of Cynthiana, directly 

 west of the railroad, I collected Strophomena vicina from lime- 

 stone boulders freshly broken out of the quarry, and stated by 

 the quarrymen to have come from the lower part of the quarry. 

 This Strophomena vicina horizon is regarded as corresponding to 

 the zone immediately below the Brannon member of the Flanagan. 



THE ROGERS GAP FAUNA, WITH A DESCRIPTION OF A FEW MILLERS- 

 BURG AND BENSON LIMESTONE SPECIES. 



On the following pages, descriptive of the fauna of the Rogers 

 Gap beds between Rogers Gap and Sadieville, the locality num- 

 bers refer to the numerous marks recently put up by the railroad 

 to indicate the location of cuts, gullies and bridges, and their dis- 

 tance from the first station in Ludlow, Kentucky, opposite Cin- 

 cinnati. Remembering that the 60-mile mark is immediately north 

 of Rogers Gap, and that the 54-mile mark is within the northern 

 limits of Sadieville, the location of the various exposures may 

 be readily determined. 



1 — Columnaria alveolata — interventa, var. nov. (Plate IV, 

 Figs. 1 A-J) — In the Benson member of the Lexington lime- 

 stone, in Central Kentucky, a variety of Columnaria alveolata is 

 very abundant. The type of this species was obtained from the 

 vicinity of Seneca Lake in Central New York, and evidently was 

 an erratic specimen. It is not known from the Trenton or Lor- 

 raine of New York, and apparently must have come from some 

 Canadian source. Without seeing the type, it is scarcely worth 

 while to speculate as to its original horizon and geographical po- 

 sition, although it usually is assumed that it was a Richmond form 

 of Canadian origin. The variety found in the Benson limestone 

 is abundant locally in Central Kentucky. Its chief characteristic 

 consists in the very unequal size of the corallites, some of the 

 corallites growing to large size, while the surrounding ones are 

 much smaller. This feature is shown best by Figs. lA, IB, al- 

 though close inspection will show similar features in Figs. ID 

 and IG. This feature is shown best by the smaller coralla with 

 the more rapidly diverging corallites, as in Fig. IC. In the larger 



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