LAMELLIBEANCHS. 113 



Aviculopecten coryanus WHITE. 



Aviculopecten coryanus White, 1874: Expl. and Sur. w. 100 Merid. , Prelim. 



Rep. Invert. FOBS., p. 21. 

 Aviculopecten coryanus White, 1877: U. S. Geog. Sur. w. 100 Merid., vol. 



IV, p. 147, pi. xi, figs. la-b. 



Like A. occidentalism but much larger, less contracted below 

 the ears, and with coarser radiating ribs. 



Horizon and Localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



Aviculopecten fasciculatusKEYEs. 



Plate xlii, fig. 7. 



Shell large, similar to A. providensis (Cox ). The ribs small, 

 in bundles of from three to four, with broad channels between 

 contiguous fascicles. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



Avicula longa (GEINITZ). 



Gervillia longa Geiniiz, 1866: Carb. und Dyas in Nebraska, p. 32, tab. ii, 



fig. 15. 



Avicula longa Meek, 1872 : U. S. Geol. Sur. Nebraska, p. 199, pi. ix, fig. 8. 

 Avicula longa Meek & Worthen, 1873: Geol. Sur. Illinois, vol. V, p. 578, 



pi. xx vi, fig. 1. ' 

 Avicula longa Keyes, 1891: Proc. Acad. Nat. Sci., Phila., p. 248. 



Shell rather below medium size, obliquely elongate, nearly 

 equivalve, with a long posterior ear and a much shorter front 

 extension. Anterior end rather acutely pointed above, sloping- 

 sinuously backward to the nearly straight basal margin ; pos- 

 terior extremity sharply rounded below. Hinge-margin straight, 

 about two-thirds the length of the valves, and extended be- 

 hind into a long narrow wing, producing a deep, rounded sinus 

 between it and the body of the shell. Forward ear broad, 

 somewhat triangular. Beaks rather prominent, situated about 

 one-fourth of the entire length of the hinge-line from the for- 

 ward end of the shell. Surface glabrate, with often fine con- 

 centric lines of growth. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 

 G 9 



