24 Aug. F. Foerste 



elevation attains a width of about half a millimeter. A much nar- 

 rower septal ridge occurs rarely in the brachial valve. In most of 

 the specimens, no trace of these septal ridges was noticed. No 

 other markings are shown by the interiors of the specimens at hand. 

 Length, 13 mm.; width, 8.7 mm. 



In Lingula briscis^ Billings, the very fine longitudinal striae 

 are characteristic, while the concentric markings are obscure. In 

 Lingula zvayneshoroenis , the conditions are reversed. 



Lingula procteri, Ulrich, is a larger and much thicker shell. It 

 is much more robust in every way, and as a result the markings 

 of the interiors of the valves are much better preserved, and in 

 greater detail. Only concentric striae and more distant undulations 

 of growth are mentioned in the original description, but obscure 

 longitudinal markings appear to be present also, judging from the 

 illustrations by Hall and Clarke. The outline of the shell also is 

 more oval. 



Orthorhynchula linneyi, James. 



(Plate III, fig. lo.) 



This species was described by U. P. James from specimens 

 obtained by W. M. Linney in the Fairmount beds of Boyle county, 

 Kentucky. It was listed from this horizon by W. M. Linney, in 

 1882, in his reports on Garrard, Lincoln, and Washington counties, 

 and in his Notes on the Rocks of Central Kentucky. In his report 

 on Clarke county, in 1884, Linney lists this species both from the 

 Fairmount beds and from the Greendale division of the Cynthiana 

 formation. 



At the upper Fairmount horizon, Orthorhynchula linneyi is 

 associated with Escharopora hilli, and Cyrtoceras vallandingliami. 

 Strophoniena maysvillcnsis occurs, although the chief horizon for 

 this species is at the base of the Fairmount. An early variety of 

 Platystrophia ponderosa also is found. Among other species may 

 be mentioned : Escharopora falciforuiis, C onstellaria florida, and 

 Phylloporina clathrata. 



Orthorhynchula lumeyi is common in the upper Fairmount 

 about a mile north of Paint Lick, in the southwestern corner of 

 Madison county. It is abundant also at the bridge south of Red- 

 house station, in the northern part of this county; and about three 

 miles west of Richmond, near the home of W. H. Parks. Three 



