Staphylinid(2 of the Amazon Valhy. 289 



tiived, the punctures being absent on a narrow space along 

 the middle. Elytra much longer than the thorax, | lin. in 

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

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

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

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

 fuscate red. 



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

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



Carraranen, April, 1874 ; a single male brought back 

 by Dr. Trail. 



Ohs, — 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 knoAvledge of the StaphylinidcB, to 

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

 of forms included in the genus itself, w^hile 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 with 

 the large horny prostei-num, 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 Acanthoglossu, 

 Stiliderus, Neognathus, Mesumius, Nazeris, Sunides, 

 Stilicopsis, Mecognathus and Dihelonetes ; 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. venfralis, S. strictus and S. marginatus, have 

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

 probably structurally very closely allied thereto ; while 

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

 iS'. pictus, must be placed in the section " Spm-ii " of 

 Erichson, their short, broad form giving them an entirely 

 different facies from the S. Jiliformis group. S. confinis 



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



