- A new flying-squirrel from the Philippine Islands
Vol 31, Page 1, Date 1918
- A new flying-squirrel from eastern Asia
Vol 31, Page 3, Date 1918
- Description of new species of shells chiefly from Magdalena Bay, Lower California
Vol 31, Page 5, Date 1918
- A revision of the viviparous perches
Vol 31, Page 9, Date 1918
- New Chinese fishes
Vol 31, Page 15, Date 1918
- Five new mammals from Arizona and Colorado
Vol 31, Page 21, Date 1918
- A new genus and three new species of North American Membracidae (Hemiptera)
Vol 31, Page 27, Date 1918
- A new subspecies of chipmunk from the Yellowstone National Park
Vol 31, Page 31, Date 1918
- A new bullfinch from China
Vol 31, Page 33, Date 1918
- A new hare from British East Africa
Vol 31, Page 35, Date 1918
- A new unstalked Crinoid from the Philippine Islands
Vol 31, Page 37, Date 1918
- Three new bats from Haiti and Santo Domingo
Vol 31, Page 39, Date 1918
- A new crinoid from New Zealand, and another from Tasmania
Vol 31, Page 41, Date 1918
- Notes on District of Columbia Juncaceae
Vol 31, Page 45, Date 1918
- Notes on Clemmys
Vol 31, Page 51, Date 1918
- Occurrence of a European solitary bee (Andrena wilkella Kirby) in the eastern United States
Vol 31, Page 61, Date 1918
- Notes and descriptions of some anthomyiid genera
Vol 31, Page 65, Date 1918
- A list of families and subfamilies of ichneumon-flies or the super-family Ichneumonoidea (Hymenoptera)
Vol 31, Page 69, Date 1918
- New plants of the Pacific Northwest
Vol 31, Page 75, Date 1918
- Two new species of fossil marine shells from California
Vol 31, Page 79, Date 1918
- A new fossil Pyramidellid Mollusk from the West Coast of America
Vol 31, Page 81, Date 1918
- Description of a new subspecies of the little yellow bittern from the Philippine Islands
Vol 31, Page 83, Date 1918
- The dimorphs of species of Chaitophorus
Vol 31, Page 85, Date 1918
- Description of a new Snapping turtle and a new lizard from Florida.
Vol 31, Page 89, Date 1918
- The earliest technical name for the Portuguese ibex
Vol 31, Page 93, Date 1918
- The status oi Perognathus longimembris (Coues)
Vol 31, Page 95, Date 1918
- A new name for an African rat
Vol 31, Page 97, Date 1918
- Nomenclatural notes on milk snakes
Vol 31, Page 99, Date 1918
- Two new manzanitas from the Sierra Nevada of California
Vol 31, Page 101, Date 1918
- Geographic variation in Citellus tereticaudus
Vol 31, Page 105, Date 1918
- A new Hydnocera (Coleoptera: Cleridae)
Vol 31, Page 107, Date 1918
- Genera of the Eupterygidae (Homoptera; Jassoidea)
Vol 31, Page 109, Date 1918
- Mutanda ornithologica iii, iv
Vol 31, Page 125, Date 1918
- Two new shrews from Oregon
Vol 31, Page 127, Date 1918
- Six new species of trees and shrubs from Mexico
Vol 31, Page 131, Date 1918
- A new marine mollusk of the genus Cerithiopsis from Florida
Vol 31, Page 135, Date 1918
- Changes in and additions to molluscan nomenclature
Vol 31, Page 137, Date 1918
- The lip-ferns of the southwestern United States related to Cheilanthes myriophylla
Vol 31, Page 139, Date 1918
- Four new mollusks from the Philippine Islands
Vol 31, Page 153, Date 1918
- Two new genera and eight new birds from Celebes
Vol 31, Page 155, Date 1918
- Three new subspecies of Passerella iliaca
Vol 31, Page 161, Date 1918
- New spiroboloid diplopods
Vol 31, Page 165, Date 1918
- A new Selaginella from Oklahoma and Texas
Vol 31, Page 171, Date 1918
- Polychaetes from Monterey Bay
Vol 31, Page 173, Date 1918
- New marine mollusks from the Philippine Islands
Vol 31, Page 181, Date 1918
- Some western species oiLathynis
Vol 31, Page 189, Date 1918
- Description of a new lole from the Anamba Islands
Vol 31, Page 197, Date 1918
- Three new Philippine Island land shells
Vol 31, Page 199, Date 1918
- The status of the genus Orchilus Cabanis
Vol 31, Page 203, Date 1918