Descriptions of'Nc%o Species of Fossils. 239 



directed to^Yard the mouth of the tube, while the conica is a flexuous 

 tube, uot composed of such rings. If there is such difference, I have 

 been unable to discover it, and until that difference is established I 

 shall insist that there is no genus Ortonia, and that the three species 

 described, from Cincinnati, by Professor Nicholson, are Conchicolites 

 corriigatus, Conchicoliles Jlexuosa (conica?) and Conchicolites minor. ^ — 

 Editor. 



Descript[o)is of New Species of Fossils from the Loxcer Silurian Formation, 

 Cincinnati Groiipi By U. P. James. 



Avicida corrugata — (James). 



. Shell (left valve) oblique, subrhomboidal ; cardinal line greater 

 than the breadth of the shell farther forward ; umbone prominent ; 

 beak compressed ; anterior ear rounded on a line with the margin of 

 the shell ; posterior ear triangular, extending beyond the margin 

 below. Anterior umbonal slope abrupt ; posterior slope gradual to 

 the point of the ear and the back margin. Surflice marked by 

 crowded concentric lines of growth, strongly corrugated from the 

 umbone to the front, giving to that part of the surface a finely sculp- 

 tured appearance, but not extending to the wings or ears. 



Breadth, measuring along the cardinal line, about one inch ; length 

 from the beak obliquely to the front, seven eighths of an irch. 



Position and locality — upper part of the Cincinnati Group, Wayne 

 county, Indiana. Collected by U. P. James. 



Avicula Welchi — (James). 



Shell oblique, about as long as broad ; cardinal line extending a 

 little beyond the margin of the shell posteriorly, forming a slightly 

 projecting ear; anterior not projecting; beak rather prominent; um- 

 bone somewhat elevated; anterior slope abrupt; posterior slope abrupt 

 to the Ijase of the wing, tlien very gradual to the margin back. Sur- 

 face mai'ked by fine concentric lines. 



Breadth of a large specimen, about three lines ; length from the 

 beak, obliquely, to the front, a little less than three lines. 



I name this beautiful little species after Dr. L. B. AVelch, of Wil- 

 mington, Ohio, an enthusiastic worker in the paleontology of South-, 

 western Ohio. 



Position and locality — upper part of the Cincinnati Group, Clinton 

 county, Ohio. Collected by U. P. James. 



