Staphylinidce of the Amazon Valley. 289 



tured, tlie punctures being absent on a narrow space along 

 the middle. Elytra much longer than the thoi-ax, | lin. in 

 length, dark bluish, rather finely but not densely punc- 

 tured. Hind body dull red, with the two apical segments 

 black. The coxje are dark red, the femora blackish, Avith 

 the basal part reddish ; the tibige and tarsi obscure or in- 

 fuscate red. 



The male has a narrow deep excision, the sides of which 

 are parallel, on the ventral plate of the 7th segment. 



Carraranen, April, 1874 ; a single male brought back 

 by Dr. Trail. 



Obs. — The form and sculpture of the head and thorax 

 render this species very easy to distinguish. 



SuNius. 



This genus is one of the most troublesome, in the 

 present state of our knowledge of the StaphylinidcB, to 

 any one dealing with a limited fauna, owing to the variety 

 of forms included in the genus itself, while at the same 

 time a number of closely allied forms have been detached 

 as distinct genera. The nineteen species here described 

 as new species of the genus possess all, I believe, in 

 common the following characters : terminal joint of 

 maxillary palpi minute, anterior coxal cavities closed 

 by the junction of the side pieces of the thorax Avith 

 the large horny presternum, 4th joint of tarsi consisting 

 of a membrane embracing the under surface and sides 

 of part of the 5th joint. This combination of characters 

 is also found, I believe, in the genera Acanthoglossa, 

 Stiliderus, Neognathus, Mesumius, Nazeris, Suiddes, 

 Stilicopsis, Mecognathus and Dibelonetes ; but in the 

 present state of our knowledge it seems to me that these 

 genera can scarcely be maintained as distinct, especially 

 while so many heterogeneous forms are still, as I have 

 said, included in Sunius. Of the sixteen species here 

 described the first six, viz., S. amicus, S. vittatus, S. ser- 

 pens, S. ventralis, S. strictus and *S'. marginatus, have 

 quite the facies of our European S. JiUformis, and are 

 probably structurally very closely allied thereto ; Avhile 

 the next four, IS. brevis, S. modestus, S. crassus and 

 S. pictus, must be placed in the section " Spurii " of 

 Erichson, their short, broad form giving them an entirely 

 different facies from the 6'. JiUfoi'mis group. S. confiais 



TRANS. ENT. SOC. 1876. — PART II. (jUNE.) U 



