lozi.'a Carboniferous Foniiations — Sardcson. 303 
The fauna is an addition geologically to our knowledge of the 
Carboniferous and is worthy of recorded description. The 
following have been collected by me and identified. 
Euomphalus springvalensis White. 
Fig. 1. 
Euuniplialus springvalensis White, 1876. Proc. Acad. Nat. Sci. Phila., 
p. 22: 1883. U. S. Geol. Sur. Terr., 12th Ann. Rt., p. 167, pi. 41, f. 
I a-b. 
Omphalotroclius springz'alensis Keyes, 1894, Mo. Geol. Sur., vol. 5, p. 
162, pi. 51, f. 7. 
This species has not been well described, tho' there is no 
doubt that the specimens in hand belong to it, since the type 
was from this place, "Kinderhook division of the Subcar- 
boniferous series Springvale, Humboldt county, Iowa." 
Springvale is now called Humboldt. 
The shell is rather large, "height about 55 mm., breadth 
of coil of last volution 70 mm., diameter of aperture 23 mm." 
Spire of six or seven volutions, a little variable, coiling at first 
in a cone with yd' apical angle, changing in last two volutions 
to wider, 102°. Umbilicus wide. Volutions narrowly in con- 
tact, flattened from the suture for a radius length to a nar- 
rowly rounded keel, below which the surface is slightly im- 
pressed. Except for these and slightly inflated peripheral and 
umbilical margins the volution is nearly circular. Surface 
smooth or with growth varices. Growth varices, indicating 
the direction of the shell aperture, run traverse from the um- 
bilical side, arch slightly forward across the periphery and 
backward at the keel making a shallow distinct sinus. 
Keyes, op. cif. reports this species from Pike county, 
Missouri, in the Lower Burlington limestone, tho' the descrip- 
tion and figure are not enough detailed to show the identity be- 
yond doubt with those at Humboldt, la. 
Euomphalus laxus White. 
Fig. 2. 
Euomphahis laxus White, 1875, U. S. Geog. Sur. looth Merid., vol- 4, 
Wheeler's rep., p. 94, pi. 5, f. 13 a-h. ; Hall and Whitfield, 1877. 
U. S. Geol. Sur. 40th Parallel, \-ol. 4, p. 260, pi. 4, f. 24 25. 
This species is reported as a characteristic one in the 
"Waverly group" of Utah, and is not heretofore known from 
Humboldt, Iowa. 
