498 PROCEEDINGS OF THE NATIONAL MUSEUM vol. m 



covered species will fall automatically and smoothly into such cate- 

 gories. 



Of the 48 species of Acrolophus treated in this revision, 27 may be 

 segregated into a total of 11 natural species groups. The members of 

 any one group are morphologically much more similar to one another 

 than they are to the remaining members of the genus. These species 

 groups cannot be correctly construed as being representatives of 

 genera until the many described and undescribed acrolophids oc- 

 curring in Mexico, Central America, and South America have been 

 thoroughly diagnosed ; at present, it is obvious that at best they may 

 be considered potential genera. The groups of related acrolophids 

 occurring in America north of Mexico are : 



1. simulatus-acornus-hicornutus 7. furcatus-punctellus 



macrogaster {complex)-baldufi 

 persirnplex-fervidus-sinclairi (com- 

 plex) 

 davisellus-serratus 

 variabilis-seculatus-macrophallus- 

 vauriei 



The remaining 21 species treated here do not show sufficient relation- 

 ship with any other acrolophids occurring north of Mexico to warrant 

 their inclusion in species groups. Eventually, however, some of these 

 isolated species will undoubtedly go into combination with other 

 species from Mexico, Central America, and South America to form 

 additional species groups. These unrelated or isolated species are: 



1. dorsimaculus 12. laticapitanus (complex) 



2. griseus (complex) 13. arcanellus 



3. texanellus 14. morus 



4. exaphristus (position uncertain) 15. forbesi 



5. filicicornis 16. panamae 



6. plumifronlellus 17. juxtatus 



7. moriipennellus 18. chiricahuae 



8. acanthogonus (position uncertain) 19. quadrellus 



9. propinquus 20. minor 



10. cocker elli 21. parvipalpus 



11. pyramellus 



Of the species treated here 44 are simple and 4 are complex, and 

 these latter may be subdivided into a total of 13 subspecific com- 

 ponents as follows: 



1. griseus (two) 3. laticapitanus (five) 



2. macrogaster (four) 4. sinclairi (two) 



