38 MISSISSIPPIAN BRACIIIOPODA 



Valves depressed convex, the anterior margin broadly rounded, ap- 

 proaching subcircular, passing gradually into the elongate, nearly straight 

 postero-lateral margins, meeting in an acute angle at the beak, which 

 is sometimes narrowly rounded. Surface marked by slender, raised, 

 regular, concentric costa?, with broad, flattened spaces between, about 

 four or five occupying the space of one millimeter in the median portion 

 of mature shells towards the front, becoming much crowded towards the 

 postero-lateral margins. 



Remarks. This species may be easily recognized by its subtriangular 

 form and by the style of its surface markings. 



Horizon. Chouteau limestone. 



GLOSSINA LINEOLATA (Rowley) 

 Plate I, Fig. 12 



1908. Lingula lineolata Rowley, Mo. Bureau Geol. and Mines, vol. 8, 2nd 

 ser., pp. 87 and 100, pi. 19, figs. 35-36 ; pi. 20, figs. 19-21. 



Description. Shell small, compressed, broadly triangularly subovate in 

 outline, the greatest width anterior to the middle. Anterior margin 

 broadly rounded and passing regularly into the lateral margins, the 

 postero-lateral margins long, gently convex, meeting at the beak, the 

 angle being 90 degrees or less. The dimensions of one of the co-types are : 

 length 8 mm., width 7.5 mm. 



Ventral (?) valve compressed, the greatest depth posterior to the mid- 

 dle, the convex curvature of the surface more abrupt to the postero- 

 lateral margins. Surface marked by strong, regular, sublamellose, con- 

 centric markings. 



Remarks. This species was described by Rowley from two specimens 

 which may possibly belong to two different species. The above description 

 is based upon the smaller of the two cotypes. In its great relative width 

 this specimen resembles the subtrigonal linguloid shells which have been 

 placed in the genus Grlossina, and by reason of that character alone the 

 species is here included in that genus. The species differs from G. 

 sedaliensis of the Chouteau limestone in its smaller size, its less acute beak, 

 and in its more crowded and more sublamellose concentric markings. 



Horizon. Louisiana limestone. 



