1972] 
Cooper — Boreus 
277 
each with 19 antennal segments, B. navasi Pliginsky (1915) (20 
segs.), and B. bey-bienkoi Tarbinsky (1962) (21 segs.). To these 
may perhaps be added B. aktijari Pliginsky (1915), described from 
a single female said by Pliginsky to have ^-segmented antennae and 
to be very like his B. chadzhi-gireji l . Nevertheless large differences 
separate each of these species from B. notoperates and B. brevicau- 
dus. None of the Eurasiatic species have the apex of tergum-10 
abruptly modified as a blade on each side; B. chadzhi-gireji and B . 
vlasovi have the 9th tergum of the male fused laterally with its ster- 
nite (Martynova, 1954) (a free suture is present in both American 
forms) 2 ; and males of B. navasi and B. bey-bienkoi have apical 
brushes of fine pubescence on the under surfaces of the hind wings 
(absent in the two American forms). It is likely that all 5 of the 
Eurasiatic species have short hypostomal bridges, like most Boreus 
but unlike B. notoperates and B. brevicaudus ; regrettably this is 
definitely known to be so only for B. chadzhi-gireji (see Pliginsky, 
1915, % 9)- 
Status of euboreus 
I have not used the generic name Euboreus (genotype Boreus 
nivoriundus Fitch) which Lestage (1940-41) proposed for all boreids 
of which the males lack transverse apophyses on abdominal terga 2 
and 3. Lestage would restrict Boreus (genotype Boreus hyemalis 
According to Martynova (1954), Pliginsky’s types of B. navasi and 
B. aktijari cannot be found, but his specimens of B. chadzhi-gireji were 
studied by her. She states that the tergal apophyses are almost (pochti) 
absent in the males of B. chadzhi-gireji. Pliginsky (1915) did not de- 
scribe the male of this species, but merely observed, in his commentary in 
German (there is an obvious misprint in the corresponding text in Rus- 
sian), that it differs from that of his B. navasi only by having 19 antennal 
segments; but the male of B. navasi is pointedly stated by him (p. 365) 
to be without apophyses on abdominal terga 2 and 3. 
2 Mickoleit (1971b) has briefly discussed the fusion of the 8th abdominal 
tergum and sternum in male Boreus. The condition of the 8th (and 9th) 
abdominal segments in male Boreus, however, is more complicated than he 
knew. Symbolizing such fusion with -f-, we have for the palearctic spe- 
cies: Boreus orientalis (8 + , 9 + ), B. chadzhi-gireji (0, +), B. semenovi 
(0, +), B. vlasovi (0, +), B. hyemalis (+, 0), and B. westwoodi (+, 
0) (see Martynova 1954); for the nearctic species: B. borealis (+, 0), 
B. calif ornicus (+, 0), B. color adensis (+, 0), B. brevicaudus (0, 0), 
B. brumalis (0, 0), B. nivoriundus (0, 0), and B. notoperates (0, 0). It 
seems that such fusions have little to tell of the larger affinities of Boreus 
that Mickoleit discusses, yet it seems clear that these fusion-patterns must 
feature importantly in any world-wide taxonomic revision of Boreus as 
now constituted. 
