StapJiijUnidcc of tJic Amazon Valley. 203 



liead, shining black, miicli longer than broad, the front 

 and hind angles rounded, the sides nearly straight, a 

 broad space in the middle smooth ; on each side with two 

 series of punctures, an irregular, somewhat double series 

 internally, and another irregular series about the outside ; 

 beneath, the marginal lines are not joined till the front 

 margin of the prosternum. Scutellum indistinctly punc- 

 tured. Elytra bright red, about as long as the thorax, 

 rather finely and not closely pimctured, the punctures 

 arranged in lines. Hind body black, with the whole of 

 the 6th and 7th segments red, finely and sparingly punc- 

 tured. Legs reddish-yellow. 



9. Xnntholinus amazonicus, n. sp. Depressns, niger- 

 rimus, nitidus, abdomine segroentis duobus ultimis totis 

 rufo-testaceis; capite subquadrato, antice minus angustato, 

 canaliculato, utrinque sulcato, angulis posterioribus acutis. 

 Long. Corp. 7 lin. 



It is possible that this insect is a local form of X. canali- 

 cnlatiis, Er., from which it differs in the shape of the 

 head, and by the whole of the 6th and 7th segments of 

 the hind body being bright reddish-yellow. 



Ega ; one individual. 



10. XanthoUnus attenuatus, Er. 

 Para ; a series of individuals. 



This species appears to be one of the most widely dis- 

 tributed and abundant of the South American Stapliy- 

 UniclcB. 



Leptacinus. 



This genus at present consists of about twenty-five 

 species, distributed over most parts of the globe ; only 

 two, however, have as yet been indicated from South 

 America. As regards the single Amazonian species here 

 described, I may remark that it differs much from the 

 ordinary form of Leptacinus by its long and slender legs 

 and scarcely spinulose tibia?, as Avell as by the greater 

 development of the prosternum ; I had at first intended 

 giving it a new generic name, but as the limits of the 

 neighbouring genera are at present uncertain, and as I 

 cannot make a sufficiently complete examination of the 

 only individual I possess, I have decided on calling it 

 Leptacinus nitidus. 



