NORTH AMERICAN ACROLOPHIDAE — HASBROUCK 489 



Mexico. By far the greatest variety of species has been collected in 

 Arizona, with the majority taken in the southeastern part of that 

 State. The actual center of distribution of the Acrolophidae is 

 probably either Central America or northern South America. The 

 family ranges considerably southward, a number of species having 

 been described from Argentina. Its members also occur on such 

 island groups as the West Indies and the Hawaiian Islands. Several 

 species have been reported to occur on both the mainland and some of 

 these islands. However, there is some question as to whether any two 

 such distantly isolated populations could actually belong to a single 

 species. 



When the present revision was begun, the majority of holotypes 

 representing the known North American species of Acrolophidae was 

 about equally divided between the United States National Museum 

 and the British Museum. The latter institution furnished photo- 

 graphs of its type material in sufficient detail to confirm the identity 

 of the species involved. In May 1951 the writer spent nine days at 

 the United States National Museum in order to study firsthand 

 the types there. It was found that 16 of the 28 holotypes at this 

 institution represented valid species, the remaining 12 proving to 

 be synonyms. The writer has been unable to examine the holotypes 

 of 7 species — those of popeanellus, plumifrontellus, arcanellus, morti- 

 pennellus, busckellus, and agrotipennellus at the Academy of Natural 

 Sciences in Philadelphia, and of texanellus at the Aluseum of Compara- 

 tive Zoology — but their identities are reasonably confirmed by informa- 

 tion relating to them in the literature. Specimens of the two species, 

 acantkogonus and exaphristus, regarded here as incertae sedis, and of 

 the subspecies, macrogaster macrogaster, have not been available to 

 the writer for study. 



Of the 22 species and subspecies described as new in this revision, 

 holotj^pes of 18 have been deposited in the U.S. National Museum. 

 In those four cases where the Museum did not receive the holotype, 

 it was presented with a paratype morphologically equivalent to the 

 holotype in order to make the collection of at least one institution 

 as complete as possible. The many paratypes resulting from this 

 revision have been widely scattered among a niunber of institutions 

 in the United States. The disposition of these paratypes is noted in 

 the treatment of each new species and subspecies. 



The writer wishes to express his indebtedness to Dr. W. V. Balduf, 

 of the Department of Entomology of the University of Illinois, under 

 whose direction this revision was made. He is also most grateful to 

 the following individuals and institutions who have collectively sent 

 on loan the slightly more than 2800 specimens upon which this study 

 was based: R. H. Beamer (University of Kansas, Lawrence); J. C. 



