ALLOCHEOMA. 443 



Whether this insect is really distinct from A. coccineum, or represents only the other 

 sex seems to me doubtful ; there are three specimens from the same locality before me 

 which all differ in the much smaller size and less elongate, more rounded and convex 

 shape, resembling closely a species of the genus Sparnus or Cyrton. The antennae 

 (though rather shorter) are identical in structure and colour with those of A. coccineum, 

 and the same may be said of the thorax, but the elytra are more finely punctured and 

 devoid of any costae ; the colour of the legs also differs from that of A. coccineum, being 

 pale testaceous, like the lower part of the face and the six basal joints of the antennae. 

 Having no intermediate forms before me, I think it right to consider A. intermedium 

 as distinct from A. coccineum. 



19. Allochroma semipunctatum. 



Black, glabrous ; head, thorax, the six basal joints and the apical one of the antennae, the anterior legs, and 

 the posterior tibiae, obscure fulvous ; elytra black, very finely punctured anteriorly. 



Length 2 lines. 



Head impunctate; the frontal tubercles narrowly transverse, bounded behind by a deep groove; clypeus 

 testaceous ; labrum and palpi piceous ; antennae distinctly incrassate towards the terminal joints, the 

 fourth and fifth joints of equal length and shorter than the third, the five lower joints fulvous, the five 

 following ones black, the last joint reddish fulvous ; thorax transverse, more than twice as broad as long, 

 the sides straight, the anterior margins not produced, the surface smooth and impunctate, glabrous ; 

 scutellum broad, piceous ; elytra with a distinct transverse depression below the base, black, finely but 

 distinctly punctate-striate, the punctuation almost obsolete below the middle ; femora piceous, the tibiae 

 and tarsi fulvous. 



Hab. Mexico, Cerro de Plumas {Edge). 



The single specimen of this species before me is distinguished from its allies by the 

 impunctate thorax, the finely punctured elytra, and the colour of the antennae. 



20. Allochroma Mvoplagiatum. 



Black ; head and thorax fulvous ; the basal and terminal joints of the antennae fulvous, the sixth joint 



thickened ; elytra finely punctate-striate, black, a transverse band at the middle of each, fulvous. 

 Length 1| line. 



Eab. Mexico, Jalapa (Edge). 



This species, of which but a single specimen was obtained, seems to be most nearly 

 allied to A. semipunctatum (with which it also agrees in size), and it is possible that 

 A. fulvoplagiatum represents but the male of that species. It differs in the colour of 

 the antennae (fulvous, with the exception of the seventh, eighth, and ninth joints, which 

 are black), and also by the elongate and thickened sixth joint ; and in the colour of the 

 elytra. The punctuation and the shape of the head and thorax is the same as in A. semi- 

 punctatum ; the elytra in the present species are, however, more deeply depressed below 

 the base and entirely black, and the fulvous transverse band is placed at the middle 

 and extends to the lateral, but not to the sutural, margin. 



312 



