172 MEMOIRS ON THE COLEOPTERA 



medio-interruptedly ridged at base, the very oblique sides merging 

 gradually through broadly rounded angles into the broadly and 

 evenly arcuate apex, the margins finely, feebly and very moderately 

 elevated throughout; suture obliterated; antennal club small; men- 

 turn setose; prothorax barely one-half wider than long, subpar- 

 allel and but slightly narrowed apically, the sides evenly and rather 

 strongly arcuate; basal angles only moderately rounded; punctures 

 distinct though not coarse, deep, remotely scattered; scutellum 

 broadly ogival, with a few fine punctures basally; elytra only a little 

 longer than wide, less than twice as long as the prothorax and not 

 wider, circularly rounded behind in nearly apical half, the sides not 

 modified in the female; surface with three rather coarsely impressed 

 and closely punctured double series of punctures and a feeble external 

 double series, the three costules very feebly convex; punctures of the 

 intervals confused suturally and more broadly externally but very 

 irregularly uniseriate medially, the punctures throughout small, 

 shallow and completely annular, not open behind; pygidium smooth, 

 finely, sparsely punctate, rather closely and finely scabriculate 

 basally and more completely laterad; last ventral (9 ) with a broad 

 polished margin throughout. Length (9 ) H-3 mm.; width 6.3 mm. 



Brazil (Rio Grande do Sul) *parvus n. sp. 



Prosternal process slender, gradually acuminate and laterally compressed 

 apically. Body black, with the legs dark piceo-rufous to dark rufo- 

 piceous throughout, highly polished, more elongate and cylindric 

 than the preceding, strongly convex; head not so short or broad, the 

 eyes a little larger; front coarsely rugose, finely, sparsely punctate at 

 base; clypeus differing greatly, short, strongly trapezoidal and flat, 

 coarsely and transversely rugose, the very oblique sides straight, the 

 apex perfectly straight, meeting the sides in very obtuse but not at 

 all rounded angles, the edges throughout thinly and sharply elevated; 

 base with a rather sharply elevated, transverse, medially interrupted 

 ridge, the fine suture behind the ridge evident; prothorax much 

 shorter, nearly two-thirds wider than long and much less than half 

 as long as the elytra, the sides evidently converging and feebly, 

 evenly arcuate from the broadly rounded basal angles to the 

 apex; punctures sparse but rather strong; base similarly broadly 

 and feebly sinuate at each side of the feeble median lobe; scutellum 

 triangular, virtually smooth; elytra fully a fourth longer than 

 wide, circularly rounded in apical two-fifths, parallel, barely wider 

 than the prothorax; punctures rather deeply impressed, relatively 

 coarse, elliptic-annular, narrowly open behind, the punctures of 

 the geminate series so close as often to be separated by broad 

 transverse septa, forming a rather rugulose surface, the general 

 punctures confused, the costules nearly flat; pygidium shining, with 

 coarse deep close-set punctures throughout; hind tarsi slender, much 

 shorter than the tibiae. Length (9) 10.8-11.7 mm.; width 5.9-6.3 

 mm. Brazil (Para), Baker. Six examples, all females. 



*parensis n. sp. 



Obsidiamis, as described above, is a species allied to rugifrons 



