186 PROCEEDINGS OF THE NATIONAL MUSEUM Vou. 113 
and reappraise, in a preliminary way, the arrangement and delimita- 
tions of the species and higher groups within the genus as it occurs 
in North America north of Mexico. This work should prepare the 
way for the solution of the more involved problems involving the 
status and natural relationships of the species and groups of species. 
Some of the problems which originally confronted the writer could 
not be solved on the basis of the material studied, and a number of 
new problems were brought to light. These are mentioned in the 
text. Many of them can be solved only by study of additional 
material and of living weevils in their natural habitats. 
MATERIALS AND METHODS 
MATERIALS EXAMINED: Most of the specimens used in this study 
were borrowed from the collections of several institutions and of a 
few private collectors. Approximately one hundred specimens were 
collected by the author. 
The abbreviations used to indicate the collections to which the 
material belongs are: AMNH, American Museum of Natural History, 
New York City; CAS, California Academy of Sciences, San Fran- 
cisco; CM, Carnegie Museum, Pittsburgh; CNHM, Chicago Natural 
History Museum; CNC, Canadian National Collections, Ottawa; 
CU, Cornell University Dept. of Entomology, Ithaca; DMA, col- 
lection of the author; ELS, collection of Elbert L. Sleeper, Long 
Beach State College, Long Beach, California; MCZ, Museum of 
Comparative Zoology, Harvard University, Cambridge; and USNM. 
United States National Museum. 
MEASUREMENTS: All measurements were made with an ocular 
micrometer in a binocular microscope. Body length was measured 
from the apices of the elytra to the front of the head between the eyes. 
The width of the elytra at the base was measured across the humeri 
at their widest point. The length of the prothorax was measured 
dorsally from the middle of the base to the middle of the apical margin. 
The width of the prothorax was measured at whatever was the widest 
point on the prothorax. The length of the rostrum was measured 
from the basal groove to the apex above the mandibles. The rest of 
the measurements do not appear to require further explanation. 
Drawinas: Figures 1-157 on pp. 217-239 were made through use 
of either a Bausch and Lomb VH microprojector or a combination of 
an ocular grid in a binocular microscope and squared paper. 
Statistics: The standard deviations (s), which have been given 
for the measurements of some species, were calculated by the machine 
method given by Snedecor (1956, pp. 55, 56). The procedure followed 
in determining the statistical significance of the difference in measure- 
