Geology — Non-Serials. 
105 
Keyes, C. R. Certain forms of Straparollus from Southern 
Iowa. Amer. Geologist, 1890, pp. 193-197. 
-Soleniscus, its Generic Characters and Relations. Amer. 
Naturalist, 1889, pp. 420-424. 
-The Bed Rock Sandstone of Marion County, Iowa. Amer. 
Jour. Science, vol. XLI, pp. 273-276. 
-Remarks on the Perisomic Plates of the Crinoids. 
__— An Annotated Catalogue of the Mollusca of Iowa. Bull. 
of the Essex Institute, vol. XX. 
- The Sedentary Habits of Platyceras. Amer. Jour. Sci., 
vol. XXXVI, pp. 269-272. 
- Genesis of the Actinocrinidae. Amer. Naturalist, 1890, 
pp. 243-254, pi. 7. 
--■ Review of the Progress of American Invertebrate Paleon¬ 
tology for the Year 1889. Ibid., 1890, pp. 131-138. 
-Review of the Progress of American Invertebrate Paleon¬ 
tology for the year 1890. Ibid., 1891, pp. 327-333. 
- The Coal Measures of Central Iowa, and Particularly in 
the Vicinity of Des Moines. Amer. Geologist, 1888, pp. 
396-404. 
- Surface Geology of Burlington, Iowa. Amer. Naturalist, 
vol. XXII, No. 264, pp. 1049-1054, plates 23, 24. 
- Discovery of Fossils in the Limestones of Frederick 
County, Maryland. Johns Hopkins University Circu¬ 
lars, No. 83. 
-Lower Carboniferus Gasteropoda from Burlington, Iowa. 
The American Species of Polyphemopsis, Sphaerodoma; 
a Genus of Fossil Gasteropods, Proc. Acad. Nat. Sci. 
Philadelphia, 1889, pp. 284-309. 
-A Geological Section across the Piedmont Plateau in 
Maryland. (A supplement to a paper by G. H. Williams 
entitled, “The Structure and Petrography of the Pied¬ 
mont Plateau in Maryland. Bull. Geol. Soc. Am., vol. II, 
pp. 301-322., pi. 12. 
