12 lAi.l' NKOGSREHd 



bv 1110 aiul iiK'Uuli'il in this work. In exceptional cases the wame charactor.s as were iiK'liulcd 

 ill the genus diagnosis are also repeated in the diagnoses of tlic species. This was done when 

 it seemed desirable to draw attention to these qualities because, to judge from the preceding 

 literature, they were perhaps not common to all the species belonging to the genus in question. 



No short, concentrated family and genus diagnoses, for the purpose of rapid orientation, 



have been given in the present work. For them the reader is referred to G. W. MOLlkr, 1912. 



descriptions of In order to obtain the greatest 2)ossible perspicuity all the diagnoses in this work have 



species. \)^Qn carried mil in as stereotyped a uianiKM' as possible. Each character has the same place 



in each diagnosis. 



On account of the incompleteness of the preceding descriptions of species 1 liave been 

 unable to give, by the side t>f the comprehensive and comparatively unwieldy descriptions 

 of species, short, summary and less unwieldy diagnoses of species. In those cases where a 

 rather large number of species of the same genus have been dealt with, a key has been drawn 

 up in order to compensate for this deficiency. 



If a species that has already been described in the literature is included in the present 

 work a complete re-description of this is given when the original description is very incomplete 

 or obviously incorrect; otherwise only a suplementary description is given. 



In some descriptions the male is given first, in others the female. The cause of this 

 inconsistency is either to be found in the nature of the material at my disposal (jr in the fact 

 that in some genera one sex — either the male or female — is easier to characterize with certainty 

 than the other. 



The absence of any information about a character in a species must not be taken as 

 indicating that in this character the species in question agrees with the most closely related 

 form. It only means that there is no information about it!! Statements as to pilosity are 

 exceptions to this rule. The absence of information as to this means that I foimd the organ 

 in question quite smooth. 



In the cases where no special remark is made about the constancy of a character in a 

 species this means that the character was practically constant in all the specimens examined 

 by me. It is of course left to subsequent investigators to discover how far this constancy 

 extends. It is to be noted that I often had a rather small amount of material of each separate 

 species at my disposal. In those cases where there was more abundant material of a species a number 

 of specimens have always been carefully investigated with regard to all the characters included 

 in the descriptions. It might quite justifiably be remarked that I ought to have stated how 

 many specimens of each species were carefully examined. By means of this a more certain 

 idea of the constancy of the separate species would, of course, have been obtained. The reason 

 why this information is not given is that it was unfortunately not included in the original 

 records of my investigations. 



It may perhaps seem superfluous to have given both exhaustive descriptions of species 

 and detailed figures. The reasons for this are as follows: l) in studying the figures given by 

 preceding authors I often felt uncertain as to the interpretation of details, 2) in many cases 

 it was impossible to show all the details and to modulate them on account of practical reasons 



