3G8 SYSTEMATIC PALEONTOLOGY 



uppermost projecting considerably beyond the dorsal margin. Antero- 

 median node large, prominent and of triangular form. Antero-dorsal node 

 projecting prominently beyond the edge, but not as high, and only about 

 half as large as the antero-median one." Ulrich, 1894. 



The types of this striking ostracod were found in the topmost division 

 (Lebanon) of the Stones River limestone of Central Tennessee. 



Occurrence. CHAMBERSBURG LIMESTONE (Tetradium cellulosum 

 bed) . Fort Loudon, Pennsylvania. 



Collections. Maryland Geological Survey, U. S. National Museum. 



Genus MAGRONOTELLA Ulrich 



MACRONOTELLA ULRICHI Euedemann 



Plate XLIII, Figs. 6-9 



Macronotella ulrichi Ruedemann, 1901, New York State Mus. Bull., No. 49, 

 p. 83, pi. vi, figs. 6-16; pi. vii, fig. 1. 



Description. " Valves three-fourths circular to subovate ; dorsal out- 

 line rarely straight, mostly prominent in the central part, specially in 

 older specimens; cardinal angles obtusely rounded to shortly truncate; 

 posterior margin with a little longer truncation, lateral and ventral 

 margins forming approximately a continuous circular line; in larger 

 specimens the anterior and posterior margins more strongly rounded, and 

 the ventral margin less curved; free edges in most specimens with a 

 broad depressed border and beveled edge. Surface strongly convex, 

 culminating in the dorsocentral region ; in some specimens almost smooth, 

 with only faint, widely and irregularly distributed circular impressions ; 

 others with very large deep pits; on the apex always a flat, smooth 

 circular area. Valve projecting slightly above the straight cardinal line, , 

 and forming a broad, low, triangular, reentrant cardinal area. 



" Dimensions : Length, 2.7 mm. ; height, 2.1 mm. ; thickness, .7 mm." 

 Euedemann, 1901. 



This fine ostracod is easily distinguished by its strongly convex valves 

 with a flat, smooth area at the apex of the surface which elsewhere is 

 marked by circular impressions or deep pits. 



