402 Mr. D. Sharp's Contributiojis to the 



impunctatus, an tennis pcdibnsque testaceis ; prothorace basl 

 medio inipresso ; abilomine basi angiistato. Long. corj). 

 Vi lin. 



Antenna) yellow, quite as long as bead and thorax, a 

 good deal thickened towards the extremity ; 3rd joint dis- 

 tinctly longer than 2nd, and a good deal longer tlian 4th, 

 which is slender and longer than broad ; of 6 — 10 each is 

 slightly longer and distinctly broader than its predecessor, 

 each a little longer than broad; 11th long, a good deal 

 longer than 10th. Head chestnut yellow, the hind angles 

 "\ery rounded, the cly])eus large. Thorax narrow, scarcely 

 so broad as the head, and not much more than half as 

 broad as the elytra ; it is longer than broad, quite convex, 

 and with an impression at the base in the middle. Elytra 

 quadi-ate, about as long as the thorax, of a chestnut colour, 

 rather darker than the head and thorax. Hind body 

 broad, but much narrowed at the base, so that its sides are 

 greatly rounded ; it is of a yellowish colom-, with the apical 

 segments a little infuscate. The legs are long and slender, 

 the four hind femora very slightly infuscate towards the 

 extremity. 



Manaos ; three individuals, captured by Dr. Trail in 

 August, 1874. They were atti'acted by light. 



Obs. — An undescribed species from Rio de Janeiro is 

 very closely allied to A. Iccv/'s, but is rather smallci-, has 

 joints 4 — G of the antenna3 longer, and the hind body more 

 contracted at the base. 



Omalium. 



The insignificant little species I here describe with this 

 genei-ic name is interesting, as being the only representa- 

 tive of the Omalini yet detected in the Amazons. Indeed, 

 the group seems to be extremely poorly represented in 

 tropical America, only two species of it having as yet 

 been described from those parts, and scarcely any others 

 existing, so far as I know, in collections ; it is, however, 

 quite ])0ssible that this paucity may prove not to be so 

 complete as these facts would suggest, for our knowledge 

 of the smaller species of tropical Staphylinidce is still so 

 very fragmentary, that no generalization as to an exten- 

 sive group can with propriety be more than hinted at. 



1. Omalium nanum, n. sp. Subopacum, depressum, 

 nigrum, antennarum basi pedibusquc testaceis; protho- 



