238 PROCEEDINGS OF THE NATIONAL MUSEUM Vou. 113 
Key to the Species of the Smicronyx instabilis Group 
1. A single patch of white scales present on each side of the median suture 
near the middle of the elytral disk and joined by a line of white scales 
which runs toward the humerus; scales of elytra otherwise yellowish brown. 
S. instabilis Casey (p. 241) 
Elytra without patches or oblique lines of white scales... ..... 2 
A smooth median line distinguishable on prothorax or punctures of protho- 
racic disk very small, sparse, difficult to distinguish among the dense 
punctulation of the surface. .. . : pene 8 3 
No smooth median line Aiememenole! on re ahorae punctuney of disk 
distinct, though not deep. . . . OG a Ee 5 
3. All scales of elytra white, rostra of both sexes neatly paente 
S. rhodopus Dietz (p. 247) 
All or part of scales of elytra yellow, rostrum seca curved in both 
to 
SOXCS aoe eac 3 oes 4 
4. Scales of protons od ciperal nuanlesacaler y allows Spies hee een punctures 
of prothorax punctulate, but not rugose . . S. dangudeles Dietz (p. 246) 
Seales of prothorax and elytra a mixture of sae and brownish yellow; pro- 
thoracic interspaces shining, raised to form low, concentric rugae. 
S. posticus Dietz (p. 240) 
5. Scales of prothorax and elytra evenly gray or yellowish gray. 
S. pusillus Dietz (p. 244) 
Scales of prothorax and elytra yellow, brown, or white. ....... 6 
6. Scales of elytra very closely spaced, pale yellowish brown mottled with 
medium to dark yellowish brown; tarsi distinctly reddish. 
S. silaceus Casey (p. 248) 
Seales of elytra rather openly spaced, yellowish brown with small scattered 
patches of white; tarsi nearly black. . . . . S. defricans Casey (p. 238) 
Smicronyx defricans Casey 
Ficurss 62, 111 
Smicronyx defricans Casey, Ann. New York Acad. Sci., vol. 6, p. 406, 1892. 
Lectotype, here designated: Male, Monterey, California, USNM 36716 
(T. L. Casey collection). 
Smicronyx nubilus Dietz, Trans. American Ent. Soc., vol. 21, pp. 149-150, 1894. 
New synonymy. Type: Female, California, MCZ 1922 (Dietz collection). 
Smicronyx celaenus Pierce, Bull. Southern California Acad. Sci., vol. 38, pp. 50—- 
52, 1939. New synonymy. Holotype: Female, El Segundo, California, 
May 18, 1938, W. D. Pierce, C. Pierce, and D. Pool. 
Description: Rostra of both sexes stout, piceous, moderately 
curved, substriate from base to apex; surface finely alutaceous, 
sparsely squamose toward the base. Head black, finely squamose in 
front. Antennae piceous throughout. Prothorax piceous, broadly 
rounded at sides, moderately narrowed and feebly constricted near 
apex; disk sparsely punctate, interspaces densely punctulate; scales of 
disk sparse, elongate and brownish yellow or elliptical and whitish. 
Elytra black; scales elliptical, except for a single row of setalike 
scales on each interval, either yellowish brown or white in color; 
