1947] 
N emestrinidce 
195 
The Catalogue covers the Dominion of Canada and the 
United States, no species being known from Alaska. 
This area includes the major part of the Nearctic Region, 
which, as is well known, extends some distance into Mex- 
ico, its southern boundary being irregular and often dis- 
puted. Two of the species here listed are known also 
from farther south, extending to Guatemala in one case 
and to Panama in the other. Moreover, most probably 
some of the other forms will also be taken eventually 
south of the Mexican border. On the other hand, three 
additional species, Neorhynchocephalus mexicanus Be- 
quaert, Hirmoneura ( Neohirmoneura ) psilotes Osten 
Sacken, and Hirmoneura ( Hyrmophlceba ) brevirostris 
Macquart, are known from Mexico and Central America. 
One or more of these might possibly yet he discovered in 
the southwestern United States. With this reservation, 
it is doubtful whether many additions will be made in the 
future to the Recent Catalogue. In any case, such addi- 
tions will not alter appreciably the general character of 
the fauna. 
Even if we include the Mexican and Central American 
forms, the Nearctic nemestrinid fauna is very scant, con- 
sisting of only nine species and one subspecies. These 
are now placed in three subfamilies and three genera, 
an unusually high proportion of supra-specific groups. 
All the species are precinctive; while one of the three 
genera only ( Neorhynchocephalus ) is strictly American, 
occurring as far south as Argentina. The other two 
genera ( Hirmoneura and Trichopsidea ) are nearly cos- 
mopolitan; but the Nearctic species belong to peculiarly 
American subgenera ( Neohirmoneura , Hyrmophlceba, 
and Parasymmictus ) . 
Throughout the world the majority of Recent Nemes- 
trinidae occur in five widely separated areas : the Nearctic 
Region; the warm temperate areas of Chile and Argen- 
tina; the Mediterranean subregion and Central Asia; 
Africa south of the Zambesi ; and Australasia. In point 
of number of species, the Nearctic Region is the poorest 
of these five areas. The Recent North American mem- 
bers of the family appear to be remnants of what may 
