AMERICAN COLEOPTERA. 



195 



Cincinnati, Ohio; one specimen, kindly given me by Mr. Harold B. 

 Wilson. The outer joints of the antennae are less obviously wider 

 than in the species figured by Spinola. 



DICENTRUS n. g. (Cerambycidas). 

 This new genus belongs to the tribe Asemini, as defined by me ;* 

 that is to say°the base of the antennae is not enveloped by the eyes, 

 and the ligula is corneous, with the bases of the palpi not retractile. 

 It belongs^o the group Opsmii, having the base of the prothorax 

 emargina°te at the middle, and the emargination filled by a depressed 

 thin plate; this emargination is however, less obvious than in Opsbnns, 

 so that the thin plate becomes merely a thin basal margin. 



Other distinctive characters are: Head short, front nearly per- 

 pendicular, eyes moderately granulated, divided as in Tetropium ; 

 palpi very unequal, maxillary moderately long, last joint elongate 

 triangular, with distal margin rounded. Antennae % a little longer, 

 9 a Httle shorter than the body; slender, first joint stouter, as long 

 as the two following ; second one-half as long as the third. Prothorax 

 a little wider than long, truncate before and behind, sides rounded, 

 armed with a small acute lateral spine at the middle, and another near 

 ihe base equally acute. Elytra not convex, wider than prothorax, 

 truncate at base, parallel on the sides, separately rounded at tip. Legs 

 moderate, thigh not clavate, hind tarsi with first joint as long as the 

 two following-united. Front coxa3 contiguous, cavities rounded, with 

 a narrow external fissure;, middle and hind coxae separated. Surface 

 opake, finely densely punctured, finely pubescent, without long hairs, 

 except a few on the antennae. 



D. BllltliMeri.— Piceous, antenna and legs brown; elytra with a large 

 spot 'extending from the sides almost to the suture, and from the first sixth to 

 the middle reddish brown; a large apical brown spot occupies the posterior 

 fourth of the elytra. Length 3—5.5 mm. 



Sierra Nevada; San Joaquim Co., Cala. ; Mr. M. S. Bliithner, to 

 whom I dedicate it with much pleasure. Dr. Horn has specimens 

 found in Nevada by Mr. H. K. Morrison, and I one from Lake 



Tahoe, (elev. 6-iG5'). 



IHOXACHIJS Chevr. 



The species of this genus are broadly oval and convex ; the claws 



are appendiculate ; the scutellum elongate, not elevated behind, and 



acutely triangular; the eyes strongly emarginate; the antennae rather 



long with the last six joints (6—11) broader. The prosternum is 



« Class. Col. N. Am. 292. 



