28 Psyche [March-June 
opening and small alulae at the zone. Furca larger or much 
larger than in Hemiargus. Sagum considerably more developed 
(and reaching in isola its maximum for the whole subfamily), 
consisting of two, ventrally scooped out or fully formed lobes 
aproning the aedeagus and armed with a set of teeth along the 
distal part or the whole of the margin. Forearm of falx very 
slightly curved and sharper than the straight blunt forearm of 
Cyclargus or Hemiargus , with a higher and more conical shoul- 
der. Uncus lobe as in Hemiargus but slightly more excurved 
and tending to a hatchet shape under pressure. Valve of a nor- 
mal subfamilial (fish-like) shape, allied to the la jus section in 
Chilades , with a tapering rostellum of the Hemiargus ceraunus 
type but differing from those genera by the presence of a bullula 
which is typical for holarctic Plebejinx (and also exists in the 
next three neotropical genera to be discussed). Female: henia 
long and comparatively thin, thus again differing from Hemi- 
argus in a normal “Old-World” direction. 
Echinargus isola Reakert 
(figs, iso, pi. 5, 7) 
Seven males and one female investigated: 
Prep. 540, “Tancitaro, Michoachan, Mexico, 6,000 ft., on 
fceces, 10-VII-1941, leg. R. Haag: 539 ( forma u nyagora Bois- 
duval”) id .; 478, “Round Mt., Texas, X-1930,” ex coll. Fall; 
$ 587, “Dallas, Texas, leg. Boll”; 500, 526, 534, “Texas”; 538, 
“Half Way House, Pike’s Peak, Colorado, 9,000-10,000 ft., 
16-18 VII-1902,” ex coll. Weeks (? ssp. alee Edwards; see 
Field 1941, Kans. Univ. Sci. Bull. 26:347). 
iEdeagus very poorly chitinised, very anemic looking when 
teased out of the prodigious structure of the sagum; just over 
two thirds of a mm. long, the suprazonal portion less than one 
third of the subzonal one with the vesical opening at two thirds 
from the zone. Furca extremely long, 1 almost reaching one mm. 
1 This is the only species of the nineteen discussed here that already had been 
(briefly) described genitalically : namely, Bethune Baker 1916, l.c., refers to “a 
large toothed hood . . . [which] has its origin just above the very short furca.” 
Evidently the greater part of the very long furca was screened from the observer 
by other parts of the armature. In this connection it should be noted that during 
the time the armatures are studied they should be kept in vials and if mounted 
at all (subsequently) the parts should be well separated, with the dorsum placed 
in ventral view. A slide of the whole armature in lateral view (or a photograph 
of such a preparation) is utterly useless. 
