6 GEO. H. HORN, M. D. 



spot could only be mistaken (in description) for j^'^Mldus or nndatus, 

 both of which have the sides of thorax broadly paler, or for coUaris 

 and tristis, both of which have the meso-coxal line. 



After an examination of the types of gnatho and labratus (labia- 

 tus II) it has been found that the two are absolutely identical, except 

 as to color. The types of gnatho are merely pale specimens. 



Occurs in the southern portion of California and the adjacent re- 

 gions of Arizona, probably extending also into Mexico. 



H. i>alli<lus Say. — Obloug, feebly convex, piceous, the elytra in great part 

 pale luteous, sides of thorax broadly pale, surface clothed with sliort. semi-erect 

 pubescence, fulvous on the paler parts, brownish elsewhere, entire margin fim- 

 briate with longer hairs. Antennte pale testaceous. Head dark browu, densely 

 punctulate. Thorax fully twice as wide as long, wider in the male, base arcuate, 

 slightly oblique each side with a distinct marginal line, disc moderately convex, 

 densely finely punctulate, color brown or piceous, the sides broadly yellowish. 

 Elytra parallel 9> or slightly narrower behind %, disc faintly striate, surface 

 densely finely punctulate, general color pale luteous, with indistinct brownish 

 markings. Epipleurse pale. Body beneath piceous, the sides of prothorax and 

 abdomen, the entire last ventral segment pale. Abdomen closely, but very mi- 

 nutely punctulate. Legs entirely pale yellow. Length .17 — .22 inch. ; 4.5—5.5 

 mm. PI. 1, fig. 2. 



3Iale. — Labium broader than long, the middle third of apical margin prolonged 

 in a process about one-third the length of the body of labrum and emarginate 

 at tip. Mandibles slender, moderately long, the teeth small and near the apex. 

 Front slightly retuse. Thorax more than twice as wide as long, sides regularly 

 arcuate, not narrowed in front. 



Female. — Labrum oval, narrowed in front, a .slight emargination at middle. 

 Mandibles shorter and stouter than in the male, the teeth more evident. Thorax 

 twice as wide as long, sides arcuate and distinctly narrowed in front. 



Variations. — The thorax may be almost entirely piceous. The 

 elytra vary also in the extent of the })allid color, which is really 

 only the expansion of the usual sinuous bands of the other species, 

 so that merely indistinct fu.scous markings appear. The underside 

 of body may vary from the described form which is in great part 

 piceous, to entirely pale, as in the specimens described by Say. 



The male is readily known. The female, when small, might be 

 mistaken for collaris, but there is no meso-coxal line in pallidus. 

 The pale elytra and entirely yellow legs will distinguish either sex 

 from any of the species in which the male has the prolonged labrum. 



Occurs in western Kansas (Popenoe) to El Paso, Texas and Ariz. 



H. Tentralis Mels. — Oblong, feebly convex, piceous, clothed with short, 

 semi-erect fulvous or bi'ownish pubescence, the entire margin fimbriate with 

 longer hair, anterior angles of thorax yellow, sometimes the entire side; elytra 



