Staphylinidai of the Amazon Valley. 29 



ledge of the South American StapliylinidcB. hitherto ob- 

 tained, however, is the descriptions contained in Erichson's 

 *' Genera et Species Staphylinorum," of species collected 

 by Moritz in Columbia, and by Beske and others in Brazil. 

 From these and from some other sources, we have had 

 altogether just about 600 species of South American 

 Stapkylinidce previously described, and, as will be seen 

 from this paper, I have been able to identify very few 

 of these described species Avith my Amazonian material. 

 There is fi-om this fact reason to su]:)pose that, as a rule, 

 the individual species of Staphylinidai have not a Avide 

 range in South America, and this opinion is confirmed by 

 all the other facts I am acquainted with. It is an inte- 

 resting point, however, that the group Piestini seems to 

 contain a much larger proportion of widely-distributed 

 species than does any other group of the family, the pro- 

 portion of new to previously-described species being in it 

 only as 3^*1. 



This number of 487 species of StaphylinidfB inhabiting 

 the Amazon valley, though it may at first appear by no 

 means inconsiderable, is yet, I feel convinced, only a small 

 fraction of the species of the group to be found in this 

 prolific region. JNlr. Bates informs me he only collected 

 the species of this family when more important and 

 valuable insects of other families were not to be met with ; 

 while out of the seventy-seven species of StaphylinidcB 

 brought back by Dr. Trail, no less than fifty-five proved 

 to be new, and not previously found by Mr. Bates. 

 Taking all I know about these insects into consideration, 

 I am unable to estimate the number of species of Staphy- 

 linidce at present existing in Amazonia at less than four 

 or five thousand species. 



This paper, therefore, lengthy as it is, is but a preli- 

 minary contribution to a knowledge of the Amazonian 

 Staphylinidai, and in executing my task I have had con- 

 stantly to bear in mind that I am only accomplishing a 

 very im])erfect work. This has been a great discourage- 

 ment to me, for recognizing, as I do most thoroughly, 

 how difficult is the task of determining obscure and small 

 species by means of descriptions, however Avell drawn up, 

 I have been often in doubt as to whether my labour Avould 

 not be wasted, or, at any rate, rewarded only by very 

 inadequate benefits to the cause of science. The certain 

 discrimination of species by means of descriptions has 



