NAPLES FAUNA IN WESTERN NEW YORK, PART 2 275 



sharp elevated ridge running from umbo to margin, narrow on top and 

 bending over to form a very narrow wing. Surface of both valves covered 

 with fine concentric striae ; no radial markings visible. 



Habitat. Genesee province ; Chautauqua subprovince. Not uncom- 

 mon in the soft sandy shales at Forestville, Chautauqua co., and Gowanda, 

 Cattaraugus co. 



Observations. This shell expresses the generic characters with some 

 variation from the genotype L. dispar, seen specially in the contour of 

 the right valve. These differences, however, are not great. In referring 

 these shells to the German species, I am expressing what seems to be their 

 closest affiliation. Freeh's description is very brief, but a study of his 

 figures fails to disclose any real difference from the New York shells, 

 unless in the contour of the smaller valve there be a distinction which 

 is here insufficiently emphasized. If our species eventually proves dis- 

 similar from L. laevis, the difference will doubtless be recognized in 

 time with a new denomination, but in the meantime the present designation 

 serves most truly to indicate its real affinities. Loxopteria laevis 

 has been found in the German Devonic only in the Clymenienkalk of 

 Wildungen. 



Loxopteria vasta sp. nov. 



Plate 13, fig. 18 



Associated with L. laevis is a large right valve, the largest of all 

 specimens observed, which differs from the valves referred to the other 

 species of the genus here present in the following particulars. The broad 

 expanded surface is very deeply depressed at the umbo, and the beak is 

 bent strongly downward at the hinge. This depression widens outward, 

 leaving in front a low, flat anterior division with a very narrow abrupt slope 

 on the margin. Back of this broad depression the surface is elevated to a 

 narrow ridgelike wing similar in character to that of L. laevis, but not 

 so abruptly raised. The postlateral surface is thus broadly concave. The 

 surface markings consist of a series of concentric wrinkles which become 

 finer and crowded toward the margin. This valve evidently indicates a 



