SMICRONYX WEEVILS—ANDERSON 191 
The sculpturing and punctation of the prothoracic disk is often 
similar among species of a given group, as in the species of the S. 
obtectus and S. ovipennis groups. However, this is not the case in 
some groups, such as the S. sculpticollis group, in which most of the 
species differ from each other in punctation and/or sculpturing of the 
disk of the prothorax. 
Enyrra: The shape of the elytra is usually similar in all the species 
of a given group, although slight differences in the prominence of the 
humeri and in the distinctness of the declivities may be detected. 
Some groups of species may be distinguished from others on the basis 
of elytral shape. For example, the elytra of the species of the S. 
ovipennis group are more inflated than those of the other groups of 
species in the subgenus Pseudosmicronyz. 
Fremora: The femora may differ in shape between species of the 
same group, as between S. resplendens Dietz, which has very strongly 
clavate femora, and S. pusto LeConte, in which the femora are not 
strongly clavate. However, no group characters have been observed 
in the femora. 
Trs1az: Although the tibiae may differ from one species to another 
in color, shape, stoutness, and scaling, the differences observed between 
species or between groups of species were either slight or rather subtle 
and have not been used as critical characters in this study. 
Tarst: As may be seen in the descriptions, the relative length and 
width of the different tarsal segments may vary between species. 
The third tarsal segment may be much broader than the first two, as 
in S. amoenus (Say), or only slightly so, as in S. obtectus LeConte and 
S. albidosquamosus Klima. The tarsal claws are more connate and 
parallel in some species than in others. However, these differences 
in tarsi are not very well defined, and have been mentioned in the keys 
and descriptions only to supplement the more important characters. 
GENITALIA: As is mentioned in the descriptions of the subgenera, 
the genitalia of both sexes show a strong tendency to be elongate in 
the subgenera Desmoris and Pseudosmicronyr and are almost never 
elongate in the subgenera Smicronyx and Pachyphanes. Thus, 
relatively important subgeneric characters have been found in the geni- 
talia. The genitalia may be similar among the species of a given 
group, as in the males of the species of the S. ovipennis group (figs. 85, 
86, 87), or they may be quite distinctive, as between the males of S. 
congestus Casey and S. sculpticollis Casey (figs. 54, 57). 
The terminal abdominal terga apparently offer little in the way 
of specific or group characters except in the species of the S. resplendens 
group, which have unusually stout spines on the hind margin of the 
propygidia of the males, and unique projections above the spiracles 
of the propygidium. 
