ON THE STATUS OF LEPTOTHORAX MAYR AND 
SOME OF ITS SUBGENERA 
By Marion R. Smith 
Bureau of Entomology and Plant Quarantine, Agricultural 
Research Administration, United States Department 
of Agriculture 
The genus Leptothoraoc was established by Mayr in 1855 
(Verh. Zool.-Bot. Gesell. Wien 5:431) for a number of Pale- 
arctic ants, such as clypeatus (Mayr), acervorum (F.), musco- 
rum (Nyl.), tuberum (F.), and unifasciatus (Latr.), without 
genotype designation. This was not done until 1903, when 
Bingham (Fauna of British India (Hymenoptera) , vol. 2, p. 
214) selected acervorum as the genotype. Ruzsky, in 1904 
(Zapiski Imp. Russk. Geogr. Obshch. 41 (1):288), described 
a new genus, Mychothoraoc , and chose the same form, acervo- 
rum, as a genotype, thus making Mychothoraoc an isogenotypic 
synonym of Leptothoraoc. W. M. Wheeler, in 1911 (Ann. N. Y. 
Acad. Sci. 21:166), overlooking Bingham’s previous designa- 
tion of acervorum as genotype of Leptothoraoc, named acervo- 
rum a second time as type of this genus. Then in 1922, Emery 
(in Wytsman’s, Genera Insectorum, fascicule 174 c:248), 
apparently unaware of the previous designation, selected cly- 
peatus as genotype for Leptothoraoc, presumably because it 
was the first species listed by Mayr in his original article ; and 
this concept has been universally adopted. However, since Bing- 
ham’s is the first valid genotype designation for Leptothoraoc , 
the genus must be based on acervorum. 
It thus becomes necessary to propose a new subgenus for 
Emery’s concept of Leptothoraoc, subg. Leptothoraoc. This 
group, which is both Holarctic and Neotropical in distribution, 
and contains a large number of North American ants, I propose 
to name Myrafant, for my wife, whose maiden name was 
Myra Fant. 
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