22 GEO. H. HORN, M. D. 



finely aurl closely punctate, intervals flat, irregularly biseriately punctulate, the 

 second and fourth intervals often wrinkled and opaque. Metasternum at sides 

 coarsely punctate, abdomen alutaceous, indistinctly punctate. xMesosternum very 

 coarsely punctate, rather shining, without opaque space and not carinate. An- 

 terior tihije smooth in front, tridentate externally a!id crenulate above, the first 

 tarsal joint a little shorter than the second. Posterior femora sparsely punctate, 

 the first tarsal joint scarcely longer than the next two. Length .18-.20 inch; 

 4.5-5 mm. 



Male.— Anterior tibial spur stout, falciform, acute at tip. 



i^ema^e.— Anterior tibial spur slender and slightly arcuate. 



The elytra are variable in color. U.sually they are in great part 

 (lull yellow with the (<uture and a broad lateral stripe piceous as in 

 comoclatm, but the alternate intervals 1-3-5-7 may be piceous, 

 united at their base and apex, rarely the entire elytra are entirely 

 black. The apices of the elytra are distinctly alutaceous and in the 

 paler specimens the side margin posteriorly and apex have a reddish 

 appearance. Specimens rarely occur with the head much less con- 

 spicuously punctured, in fact comparatively smooth, this is indepen- 

 dent of sex, although the females are generally rougher. 



Two specimens from Washington Territory are before me with the 

 intervals 2 and 4 not wrinked and opaque, those may represent 

 another species as there are other slight differences, but with such a 

 close resemblance to the others I am unwilling to separate them with 

 so little material. 



Occurs in California (and ? Wa.shington Territory). 



A. alternatus Horn. — Moderately elongate and convex, parallel, black, 

 shining, legs brownish or piceous, elytra variable, usually with intervals alter- 

 nately dull yellow and piceous. Antennse rufous, club darker. Head moderately 

 convex, front not tuherculate, sparsely rather finely punctate; clypeus broadly 

 and feebly emarginate at middle, the angles broadly rounded, sides oblique 

 slightly sinuate posteriorly, geufe moderately prominent, but obtuse. Thorax 

 nearly twice as wide as long, slightly narrower in front, sides very feebly arcuate, 

 hind angles obtuse, base arcuate, the marginal line distinct only at the sides; 

 disc finely not closely punctate, regularly disposed and very little coarser near 

 the sides. Elytra as wide at base as the thorax, humeri obtuse, disc sti'iate, the 

 punctures moderately coarse and close, intervals flat, irregularly biseriately, 

 moderately coarsely punctate, intervals not alutaceous. Body sparsely indistinctly 

 punctate beneath. Mesosternum coarsely punctate, often with a broad smooth 

 space at middle. Anterior tibife smooth in front, tridentate externally and ser- 

 rulate above, the first tarsal joint shorter than the second. Posterior femora 

 sparsely punctate, the first tarsal joint not as long as the next three. Length 

 .18-.23inch; 4.5-6 mm. 



Male. — Antei'ior tibial spur stout, straight, curved and acute at tip. 



-FewiaZe.— Anterior tibial spur slender, slightly curved, acute at tip. 



