264 SYSTEMATIC PALEONTOLOGY 



BAFINESQUINA MINNESOTENSIS INQUASSA (Sardeson) 

 Plate XLV, Figs. 5, 6 



Strophomena inquassa Sardeson, 1892, Bull. Minnesota Acad. Nat. Sci., 



vol. iii, p. 334, pi. v, figs. 22-24. 

 Rafinesquina minnesotensis var. inquassa Winchell and Schuchert, 1893, 



Geol. Minnesota, vol. iii, p. 403, pi. xxxi, figs. 27, 28. 



Description. The brachiopod to which this varietal name has been 

 applied differs from R. minnesotensis in its larger and more convex shell 

 with a wide ventral hinge area. Externally this shell also has a consider- 

 able resemblance to R. alternata., but the interiors of each exhibit con- 

 siderable difference, the two ridges on each side of the median septum in 

 the present variety being reduced to one in R. alternata. 



Occurrence. CHAMBEESBUEG LIMESTONE (Echinospherites bed). 

 Southern Pennsylvania and at Pinesburg Station and Wilson, Maryland. 



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



RAFIXESQUIXA SQUAMULA (James) 

 h Plate LIV, Figs. 3-4; Plate LVIII, Fig. 4 



Strophomena squamula James, 1874, Cincinnati Quart. Jour. Sci., vol. i, 



p. 335. 

 Raflnesquina squamula Foerste, 1914, Bull. Sci. Lab. Denison Univ., vol. xvii, 



p. 264. 



Description. " Shell small, thin, semi-oval in outline, broader than 

 long ; hinge-line varying from a little more to a little less than the greatest 

 breadth of the shell farther forward. 



" Dorsal valve slightly convex or nearly flat ; cardinal line straight ; 

 cardinal area linear ; a slight 'depression immediately forward of the beak. 

 Surface covered with fine, rounded radiating striae of nearly uniform 

 size, increased toward the free margin by bifurcation. 



"Ventral valve slightly convex; beak and hinge-line slightly project- 

 ing; cardinal area narrow, a little the widest in the middle; foramen 

 triangular and nearly closed by the cardinal process of the other valve; 

 a strong mesial rib extending from beak to the front ; surface covered by 

 fine, rounded, radiating striae, which bifurcate once or twice before 



