-
Two new North American butterflies
Vol 20, Iss 1, Page 5, Date 1930-10
-
The vegetation of the Fort Reliance sand-plain
Vol 20, Iss 1, Page 9, Date 1930-10
-
Notes on some American butterflies mainly relating to classification and nomen-clature. Parts 2 and 3
Vol 20, Iss 1, Page 39, Date 1930-10
-
Crawfishes of the Southern Appalachians and the Cumberland Plateau
Vol 20, Iss 2, Page 61, Date 1931-06
-
List of types of Crustacea in the Carnegie Museum on January 1, 1931
Vol 20, Iss 2, Page 161, Date 1931-06
-
List of types of Pelecypoda in the collections of the Carnegie Museum
Vol 20, Iss 2, Page 171, Date 1931-06
-
List of types of Amphineura and Gastropoda in the collection of the Carnegie Museum on January 1., 1931
Vol 20, Iss 2, Page 179, Date 1931-06
-
Notes on some American butterflies, mainly relating to classification and nomenclature. Pt. 3 (Cont’d from p. 55).
Vol 20, Iss 2, Page 255, Date 1931-06
-
An undescribed water strider from Brazil (Hemiptera-Gerridae)
Vol 20, Iss 2, Page 267, Date 1931-06
-
Leptoypha, an American genus hitherto unknown as occurring in Palearctic Asia. (Hemiptera, Tingitidae)
Vol 20, Iss 2, Page 269, Date 1931-06
-
A new subspecies of the Arizona Gray Squirrel (Sciurus arizonensis Coues)
Vol 20, Iss 2, Page 271, Date 1931-06
-
Earl Douglass. A sketch in appreciation of his life and work
Vol 20, Iss 3-4, Page 279, Date 1931-06
-
The Upper Uinta Formation of northeastern Utah
Vol 20, Iss 3-4, Page 293, Date 1931-06
-
New species of the genus Teleodus from the Upper Uinta of northeastern Utah
Vol 20, Iss 3-4, Page 307, Date 1931-06
-
A list of the land-snails of Pennsylvania, with a summary of their distribution
Vol 20, Iss 3-4, Page 313, Date 1931
-
New Mesonychids from the Uinta
Vol 20, Iss 3-4, Page 333, Date 1931-06
-
Two new species of Agriochoerids
Vol 20, Iss 3-4, Page 341, Date 1931-06
-
Errata and Corrigenda
Vol 20, Page ix, Date 1931