264. PROCEEDINGS OF THE NATIONAL MUSEUM Vou. 113 
Key to Species of the Smicronyx amoenus Group 
1. Scales of prothorax and elytra mostly white, mottled with broken patches of 
light brown scales; rostrum of female rugose punctate laterally before the 
antennal insertions, rostrum of male bearing a fine median carina behind 
antennal insertions; prothorax black or nearly so. 
S. convexus, new species (p. 266)4 
Seales of prothorax and elytra mostly light or dark brown; white scales in 
basal patches on prothorax, in wavy transverse fasciae or short vittae on 
elytra; rostrum of female punctate but not rugose laterally before antennal 
insertions, no median rostral carina in males (although there may be a 
smooth median line); prothorax light or dark reddish brown. 
S.amoenus (Say) (p. 264)> 
Smicronyx amoenus (Say) 
Ficures 72, 120 
Tychius amoenus Say, Descriptions of new species of curculionites . . ., p. 26, 
1831. Type: believed destroyed. Neotype, here designated: Female, “‘Mis- 
suri,’ collected by Thomas Say, Naturhistoriska Riksmuseet, Stockholm. 
Description: Rostra of both sexes reddish brown to piceous, 
stout, moderately curved, substriate; finely punctured before antennal 
insertions, more closely and coarsely punctate and thinly squamose 
behind the antennal insertions. Antennae reddish brown to piceous. 
Prothorax reddish brown to piceous, strongly rounded on sides, 
narrowed and slightly constricted toward apex; covered with a 
mixture of light brown and dark brown ovate scales, which are oriented 
from sides and base toward midline; two triangular patches of white 
or yellowish scales on each side of midline at base. Prosternum 
shallowly emarginate, slightly concave. 
Elytra reddish brown, intervals covered with scales of same colors 
as those of prothorax, the light brown scales (white in some specimens) 
arranged in transverse wavy bands; humeri distinct, but not promi- 
nent; declivities indistinct. Underside of the thorax and abdomen 
covered with white or light brown scales, which are broader and more 
rounded than those of dorsum. Femora clavate, reddish brown, 
covered with ovate and elongate light brown scales. Tibiae stout, 
reddish brown, the first two pair slightly expanded at the apex, third 
pair more strongly expanded at apex. Tarsi piceous, segment three 
broader than first two segments; claws small, subparallel, connate in 
about basal third. Spiculum gastrale of male genitalia curved, but 
not hooked or expanded at anterior end (fig. 72). Stem of spiculum 
ventrale of female not expanded at anterior end (fig. 120). 
MeaAsuREMENTS: The following measurements were taken from 6 
males and 5 females from Glen Echo, Md. (USNM), 3 males and 1 
4 Presently known only from the Great Basin region. 
5 Not known to occur west of the Great Plains region. 
