AN ABERRANT NEW GENUS OF 
MYRMICINE ANT FROM MADAGASCAR 1 
By William L. Brown, Jr. 
Department of Entomology 
Cornell University 
Ithaca, New York 14853 
During a research trip to the Old World tropics during January 
to April 1977, I was allowed by M. A. Peyrieras, of the Institut de 
Recherche Scientifique of the Malagasy Republic in Tananarive, to 
sort through some berlesates of humus and leaf litter collected by 
him in various parts of Madagascar. Among these samples, I dis- 
covered a single worker example of an extraordinary new genus 
and species of Myrmicinae. M. Peyrieras has my thanks for these 
and many other interesting samples, including several undescribed 
species of ants. Among these are the first recorded representatives 
of Discothyrea and Amblyopone found on Madagascar, to be de- 
scribed in a separate publication. The new genus is described next 
below. 
Pilotrochus new genus 
Worker: Subfamily Myrmicinae, tribe unknown. Integument 
thick and rigid. Head subpyriform, slightly depressed but convex, 
broadest behind, without posteromedian excision; frontal carinae 
far apart, at sides of head, produced laterad angularly above an- 
tennal insertions, continuous posteriad with the sharp upper mar- 
gins of deep and broad antennal scrobes occupying about 2/3 of 
length of sides of head; eyes small, situated on ventral borders of 
scrobes near their posterior ends, slightly posterior to midlength 
of head. Antennae 8-merous, scapes short and thick, much nar- 
rowed basad; club distinctly 2-merous, slightly longer than re- 
mainder of funiculus, apical segment about twice as long as 
•Hymenoptera: Formicidae. A report of research from the Cornell University 
Agricultural Experiment Station. Research supported by National Science Founda- 
tion Grant DEB 75-22427. 
Manuscript received by the editor February 3, 1978. 
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