146 The American Geologist. September, i892 
his collection in my hands for examination. All the recognizable 
species belong either to the Gasteropoda or Cephalopoda. Indeed 
all the species belong to one or the other of the above gronps ex- 
cept some amorphons, laminated, porous structures that recall 
certain forms of the St romat oporo idea . 
The following species, all apparently confined to cherty layers 
of the formation, may be noted: 
Metoptoma alta W/u'tJicld. The collection contains speci- 
mens apparently identical with the species described and figured 
by Mr. R. P. Whitfield under the above name in his paper on 
Fossils from the Calciferous Sand-rock of Lake Champlain^ Bul- 
letin of Am. Museum of Natural History, Vol. ii, No. 2. The 
Iowa specimens referred to this species are larger than those from 
Lake Champlain. With the above occur two or three other species 
of Metojyfoma. 
Triblidium, sp. There are a few forms presenting the appear- 
ance of Capulus or Platyceras that probably belong to this genus. 
Straparollus claytonensis, n. sp. This is by far the most 
common species in the collection. It resembles Euomphalus cal- 
ciferus Whitfield, Lake Champlain Fossils, p. 47, plate viii, figs. 
12 and 13. The volutions are four or more in number, circular 
in transverse section; umbilicus wide and deep; spire sometimes 
almost flat, usually slightly elevated. From E. calciferns W., 
this species will be distinguished by the fact that the volutions, in 
the cast, are not embracing, scarcely touching each other, and the 
volutions ai^e not coiled in the same plane. The two forms are 
about equally robust and the whorls expand at about the same 
rate. Straparollus cho/toueiisis differs from EnoinphaJxs strongi 
Whitfield, in the greater number of less rapidly expanding volu- 
tions, the absence of caringe or angles on the whorls and the pro- 
nounced difference between the umbilical and opposite sides. 
Straparollus prlstiniformis, n. sp. This is a smaller form 
than the preceding; volutions less robust, not embracing or 
slightly separated in the cast, coiled in the same plane so that 
the spire and umbilical sides are similar in appearance; whorls 
nearly circular in transverse section, upper surface of each marked 
by an obscure carina, with traces of another carina still more ob- 
scure half way between the middle of the whorl and the suture. 
Raphistoma pepinense Meek. The collection contains many 
specimens of this very beautiful species. The spire is depressed 
