78 Memoirs on the Coleoptera 



inent. Length 1.9 mm.; width 1.15 mm. Brazil (Chapada). August. 



One specimen trepidus n. sp. 



Form narrower, more rhombic-oval, the humeri slightly more prominent, obscure 

 rufous, the prothorax a little brighter; entire surface shining, though feebly 

 micro-reticulate; beak rather slender and arcuate, much longer, even some- 

 what longer than the head and prothorax, finely, not very densely punctate, 

 the antennae normal; prothorax somewhat shorter than wide, the moderately 

 converging sides feebly and subevenly arcuate throughout, but little more 

 so near the scarcely subtubulate apex, which is fully half as wide as the 

 base, the lobe moderate, somewhat sinuato-truncate at apex; surface finely, 

 remotely punctate, with smooth median line, the punctures gradually a little 

 coarser and less remote laterally and rather coarse and close throughout the 

 inferior flanks; a dorsal series along the base is also more distinct, as in the 

 preceding; scutellum minute, quadrate, wider than long and feebly concave; 

 elytra nearly as in trepidus but with the sides somewhat less converging and 

 the apex a little more broadly rounded; grooves smooth and deep, 7 and 8 

 evidently finer and more punctulate; intervals flat, nearly smooth; hind 

 tibia? similar. Length 1.65 mm.; width 0.9 mm. Brazil (Chapada). 

 November. One specimen trivialis n. sp. 



The almost identical form of the head in breviuscahis, with its 

 conspicuous abrupt and very deep cavity, to that of the species of 

 Melanolia mentioned above, together with similarities of general 

 organization, especially tibial, antennal, prosternal and abdominal, 

 shows that there is probably no real generic difference between 

 Melanolia and Hiotopsis, but the distinction here made is at least 

 useful taxonomically, as becomes evident on casual inspection of 

 the two series, which contrast so greatly in size and shape of the 

 body. 



Group IV. 



Subgenus Spermidius nov. 



Four aberrant minute species are here regarded as forming a 

 subgeneric group, although they include four rather isolated types 

 of structure; they all agree, however, in the general characters of 

 the tribe, and, among themselves more especially, in having the 

 outer contour of the hind tibiae evenly arcuate basally, without 

 trace of the truncature and acute angle or tooth of the preceding 

 subgenera, resembling the singular Idiopsida in this respect. Their 

 special characters are brought out more definitely in the following 

 descriptions: 



Sutural stria prolonged outwardly at base, the surface between the suture and 

 stria upwardly oblique from the suture basally; discal striae wholly obsolete. 

 Body narrowly subrhombic-oval, deep black and polished, the entire pro- 

 thorax dark rufous, the elytra darker piceo-rufous; beak thick, feebly 

 arcuate, as long as the head and prothorax, somewhat compressed and 

 strongly but not densely sculptured, finely and sparsely so above; antennal 

 club long and rather slender; prothorax nearly as long as wide, the sides 

 distinctly converging and straight, gradually and slightly rounding anteriad 



