FOSSILS OF THE CARBONIFEROUS. 



251 



of fishes and a genus of insects (Miller's Cat. Pal. Foss., Addenda, p. 244, 

 1877). In the Paleontology of New York (vol. v, part 1; Plates and Ex- 

 planations, p. 18, 1883), a second generic name is placed between Microdon 

 and Eodon, viz, Microdonella. Professor Hall previously described the genus 

 Cypricardella for similar forms from the Warsaw limestone (see remarks by 

 Mr Whitfield, Bull. Amer Mus. Nat Hist, vol. i, No. 3, p. 63), and if Micro- 

 don is dropped Cypricardella will have to be substituted. 



Formation and localities. Lower portion of Lower Carboniferous lime- 

 stone in the cafion north of Pinto Peak, and also on the east slope of a small 

 conical hill on the east side of Secret-canon-road Canon, Eureka District, 

 Nevada. 



Genus CARDIOLA Broderip. 



Cardiola ? filicostata, n. sp. 

 Plate xxii, figs. 4$ 4 a. 



Shell obliquely oval, moderately convex. Beak somewhat elevated, 

 small and incurved. 



Surface marked by fine, radiating, slightly irregular, elevated striae, 

 and a few concentric lines of growth. 



Interior characters unknown. 



Dimensions: height, 1.5 cm ; width, 2 cm ; convexity or depth of left 

 valve, 0.5 cm . 



The generic reference is doubtful, owing to the absence of the interior 

 characters, and also the strong surface costse, so characteristic of Cardiola. 

 The only related species referred to the genus is Cardiola transversa Hall 

 (Pal. N. Y., vol. v, pt, 1 ; Plates and Explanations, pi. Ixx, figs. 12-15). 



Formation and locality. Lower portion of Lower Carboniferous lime- 

 stone on east slope of a small conical hill on the east side of Secret-canon- 

 road Cation, Eureka District, Nevada. 



