378 The Ohio Journal of Science [Vol. XIX, No. 7, 



ulose, the granules tending toward linear arrangement along the crests 

 of the fine radiating lines which correspond to the grooves between 

 the radiating striae characterizing the exterior of the shell. From the 

 bilobed cardinal process short thickened lines of elevation extend 

 obliquely forward, limiting the postero-lateral outlines of the muscular 

 area. A short, low, but broad line of elevation also extends from the 

 cardinal process straight forward, dividing the muscular area. 



In our present state of knowledge of the Stropheodontoid 

 shells of the Clinton group of New York, it is scarcely worth 

 while to attempt to correlate any of the West Union forms w^ith 

 the latter. To me, the Leptaena obscura, from the upper ore 

 beds of the typical Clinton, appears to be a Schuchertella. 

 I strongly suspect that Stropheodo?ita prisca is identical with 

 Leptaena orthididea, being associated with the latter in the 

 iron beds of the typical Clinton. Both belong to the subgenus 

 Brachy prion. Leptaena corrugata, another Stropheodontoid, is 

 said to be most abundant in the upper green shale of the 

 Clinton and in the Pentamerus limestone member beneath. 

 Leptaena profunda, another Stropheodontoid, was described 

 from the Irondequoit limestone. From among these species, 

 the West Union specimens appear most nearly related to 

 Stropheodonta orthididea. 



Stropheodonta (Brachyprion ) newsomensis Foerste. 

 Plate XVIII, Figs. 1 A-C. 



In the Ilolophragma zone, at the top of the Upper or Lilley 

 member of the West Union formation, in the Zink or Corpora- 

 tion quarry, within the eastern limits of Hillsboro, Ohio, a form 

 of Brachyprion, here figured, is not uncommon. It belongs 

 to the more elongated forms of this genus. 



Ratio of length to width 82-85 per cent. About 7 or S stri« occupy a 

 width of 2 millimeters. The muscular area of the pedicel valve is 

 bounded laterally by diagonal extensions of the dental lamellae. There 

 is a median septal ridge terminating posteriorly in a small, triangular 

 callosity, with two of its angles directed diagonally toward the front. 

 Near the foramen, the lower part of the hinge area is vertically striated, 

 and beyond the striated area the interior of the shell, beneath the hinge 

 area, is thickened by a linear callous growth. The cardinal process of 

 the brachial valve consists of two lobes, grooved along the top, forming 

 approximately a right angle with each other. From the base of these 

 lobes two low, broad callosities, bordering the sides of the posterior 

 part of the muscular area of this valve, can be traced diagonally forward 

 for a distance of three or four millimeters. From the bases of the same 



