Fauna of the Morrow Group 
213 
1884. Nuculana bellistriata. White, 13th Rep. Geol. Surv. Ind., p. 146, 
pi. 31, figs. 8-9. 
Coal Measures: Vermilion, Sullivan, Vandenburg, and Warrick 
Counties, Indiana. 
1887. Nuculana bellistriata. Herrick, Bull. Sci. Lab. Den. Univ., vol. 2, 
p. 40, pL 4, fig. 26. 
Coal Measures: Flint Ridge, Ohio. 
1888. Nuculana bellistriata. Keyes, Proc. Acad. Nat. Sci., Phil., p. 232. 
Lower Coal Measures: Des Moines, Iowa. 
1894. Nuculana bellistriata. Keyes, Mo. Geol. Surv., vol. 5, p. 122, pi. 
46, figs. 4a-b. 
Upper Coal Measures: Gentry and Kansas City, Missouri. 
1897. Nuculana aff. bellistriata. Smith, Proc. Am. Phil. Soc., vol. 35, 
p. 35, 
Upper Coal Measures: Scott County, Arkansas. 
1900. Nuculana bellistriata. Beede, Univ. Geol. Surv. Kans., vol. 6, p. 
148, pi. 20, figs. 14-14b. 
Upper Coal Measures: Kansas City, Rosedale, Lawrence, and 
Topeka, Kansas. 
1903. Leda bellistriata ?. Girty, Prof. Paper, U. S. Geol. Surv,, No. 16, 
p. 442. 
Upper portion of Hermosa formation: San Juan region, Colorado. 
1911. Leda bellistriata. Mark, Bull. Sci. Lab. Den. Univ., vol 16, p. 310, 
pi. 9, fig. 5. 
Mercer limestone: Limestone Hollow, Flint Ridge, Ohio. 
Description. Shell transversely sub-oval, moderately convex, 
length to height about as seven to four; posterio-dorsal margin 
slightly concave and produced posteriorly meeting the ventral 
margin in an acute angle; ventral margin convex, somewhat 
strongly anteriorly and more gently posteriorly, joining the 
anterio-dorsal margin in a broad curve; anterio-dorsal margin 
broadly convex; beak full but not elevated far above hinge-line, 
situated in front of the middle, greatest convexity a little in 
advance of the middle; surface ornamented by close-set, con- 
centric, angular ridges separated by rounded grooves and occur- 
ring about 3 to the millimeter in the ventral portion of the shell. 
The dimensions of the specimen figured are approximately: 
length, 13.5 mm. ; height, 8.2 mm. ; convexity of valve, 2.3 mm. 
Remarks. These shells are not so transversely elongate as 
the Coal Measures forms commonly referred to this species but 
the dimensions of the type specimen, as given by Stevens, are: 
length, 0.7 inch; height, 0.4 inch; giving an outline closely sim- 
