Crown length of cheekteeth: From the anterior border of P4 to the posterior border of M3.
In the accounts of species, measurements of aristiforms and setiforms are used. The hairs measured were taken from the middorsal region and outer thighs, and the measurements are means.
All specimens of which measurements are here recorded, as for example in the tables, are fully adult; each specimen shows some wear on each of the four upper molariform teeth unless otherwise indicated.
Capitalized color terms are after [Ridgway] "Color Standards and Color Nomenclature," Washington, D. C., U. S. A., 1912. One setiform was taken from the animal and placed over the rectangles in [Ridgway's] charts and the examination made under a microscope with low (×7) magnification and natural light. This method was found to give the most satisfactory results.
The following abbreviations are used for names of institutions:
AMNH—American Museum of Natural History.
CNHM—Chicago Natural History Museum.
DZ—Departamento de Zoologia da Secretaria de Agricultura, São Paulo, Brazil.
MCZ—Museum of Comparative Zoology at Harvard College.
MN—Museu Nacional, Brazil.
MZ—Museum of Zoology, University of Michigan.
SEPFA—**Serviço de Estudos e Pesquisas sobre a Febre Amarela, Brazil.
USNM—United States National Museum.
UZM—Universitets Zoologiske Museum, Copenhagen.
[ACKNOWLEDGMENTS]
Approximately two thousand skins and skulls were assembled at the Museum of Natural History, University of Kansas, through the coöperation of the authorities in the various institutions of North America, Brazil and Denmark, as listed immediately above. This comprehensive material was used to obtain a more complete understanding of the group, and for the loan of these specimens I am extremely grateful to the authorities of each of the institutions.