DIAPERESri NORTH OF MEXICO — TRIPLEHORN 353 



based have passed through several hands and those that have not 

 been totally destroyed are in such a state of disarrangement that 

 they are unrecognizable. The descriptions of Laporte and Brulle are 

 accurate and very clear, so that recognition of their species is for the 

 most part relatively easy. 



Motschoulsky (1873) proposed a number of names for North Amer- 

 ican species of Diaperini which until now have either gone un- 

 recognized or have been misapplied. It is doubtful that he ever 

 consulted any existing works (e.g., Horn's revision, 1870) since he 

 described everything he encountered as new. Fortunately, he was 

 a keen observer and a very fine writer, so that all of his species are 

 recognizable and all but one of his North American species may be 

 irrefutably placed as synonyms under older names. 



In direct contrast stand the taxonomic endeavors of Chevi'olat 

 (1877a, b, 1878). Happily for this study, he encountered very few 

 of the North American species, but the multitude of names which 

 he has proposed for South and Central American species, all accom- 

 panied by unnecessarily brief and inadequate descriptions, has made 

 it virtually impossible for anyone to work inteUigently with species 

 from these regions. Some of his descriptions could apply to any num- 

 ber of species. Also, he chose to publish in the Petites Nouvelles 

 Entomologiques, a relatively obscure and not generally available jour- 

 nal. Finally, he presented neither keys nor synopses of his species, 

 merely registering a short description of species after species with 

 practically nothing of a comparative natm'e mentioned. 



Morphology and terminology. — Each genus and species is fully 

 described in what is hoped to be clear and understandable terms. In 

 many instances, great emphasis is placed upon characters which, in 

 the final analysis, are relative in nature. Such characters are, in 

 themselves, highly objectionable but unavoidable in many cases. 

 Quite often these descriptions presuppose a familiarity with some 

 closely related species. This was done intentionally in order that 

 the reader will have some point of reference. Where practicable, 

 illustrations have been prepared to ehminate some of the guesswork, 

 particularly in regard to characters used in the keys. 



The only new character which has been utilized to any appreciable 

 extent is the structure of the male genitalia. The terminology is 

 essentially that of Sharp and Muir (1912), Blaisdell (1909, 1939), 

 and Lindroth and Palm^n (1956j, all of whom more or less agree. It 

 is not the purpose of this paper to delve deeply into the controversies 

 attending such studies but to use these structures as taxonomic im- 

 plements. For this purpose, the male aedeagi were useful in the 

 broader classification aspects, but were seldom necessary in distin- 

 guishing between species. 



