370 SUPPLEMENT. 
To the localities given, add :—Honpuras, San Pedro Sula (Williamson, coll. ejusd.: 
6 ¢), Ruatan I. (Gawmer: 1 9); Costa Rica, Esparta [21 ¢, 5 ¢], Surubres 
[2 ¢,1 2] (Biolley, coll. Kahl), Rio Jesus Maria (Biolley: 2 3,2 ¢), Juan Vifias 
(Bruner, U. S. N. M.: 1 2), Quebrada del Cangrejal (Biolley, colls. A. N. 8S. & 
Wiimsn.: 12 ¢, 7 ¢).—Cotomsia, Bonda in Dept. Magdalena (H. H. Smith, Carn. 
Mus. Pittsb.: 1 9); Ecuapor, Bucay, not Duran (Campos R., A. N.S.: 1 3). 
This species is closely related to A. oculata, and we have called attention, anted, 
p. 368, to the pairing of A. diffictlis females with A. oculata males. That this is 
possible is, perhaps, due to almost complete identity in shape of the abdominal 
appendages of the males of the two species. A. difficilis males differ from A. oculata 
males in the duller blue of the pale areas of the body (cf the “bleu vif” of the 
original description of the abdomen of ocwlata) and the less extent of the mid-dorsal 
stripes on abdominal segments 3-6. A. difficilis females differ from A. oculata 
females in the shape of the mesostigmal lamina, in the black labrum and nasus of the 
adult, and in the absence even in teneral individuals of a pale mid-dorsal stripe on 
segments 4 and 5. From the data given above, it would appear that, ontogenetically, 
difficilis females pass through a stage with pale labrum and clypeus which is 
permanent in oculata females. 
16 (a). Argia underwoodi, sp.n. (Tab. VIII. figg. 36, 37, 37 s.) 
¢. Rear of head black, a pale line along the eye-margins inferiorly. Labrum dark violaceous. Pale ante- 
humeral stripe one-third as wide as the black mid-dorsal stripe, which latter has a dull dark metallic- 
green reflection. Black humeral stripe (in some at least with a dull dark metallic-green reflection) one 
to one and one half times as wide as the pale antehumeral, enclosing a pale spot at its upper end. 
A black stripe on the second lateral thoracic suture a little narrower than the humeral stripe. Pale 
colours of the thorax violet-blue. Abdominal segments 2 and 3 violet-blue, each with a black stripe 
each side as long as the segments, each black stripe on 2 giving off an anteapical projection on to the 
dorsum toward its fellow of the opposite side, black stripes of 3 uniting on dorsum for the apical fourth 
of the segment; 4-7 black, with a transverse basal pale ring, interrupted dorsally ; 8-9 blue, with an 
inferior longitudinal black stripe each side as long as the segments; 10 black. The black of the anterior 
abdominal segments may have some metallic-green reflection. 
Q. Differs from the male as follows :—Rear of head black with a transverse pale stripe at mid-height, 
widest at eye-margins. Pale antehumeral stripe subequal in width to the black mid-dorsal. Black 
humeral stripe one-half as wide as the pale antehumeral. Pale colours of thorax reddish violet, the 
black stripes with no metallic reflection. 
¢ 2. Pterostigma of front wings *8 (d), *9 (Q) mm. long, surmounting one cell (55°6 °/, 3,50 °/. 2), 
more than one cell (38°6 9/, 3, 50 °/, 2), or less than one cell (5°6 °/, 5); of the hind wings 1 mm. 
long, surmounting more than one cell (83°3 °/, §, 100°/, 2) or one cell (16°7 °/, 3). 
Antenodal cells on the front wings 3 (94°5 °/, g, 100 °/, 2) or 4 (55 °/, 3); on the hind wings 3 
- (100 %/, 5 2). . 
Di nensions.—Abdomen, ¢ 28°5-32, 9 27:5; hind wing, ¢ 21°5-28, 2 24 mm. 
Hab. Costa Rica, Carrillo (C. F. Underwood: 9 3,1 2). 
16(s). Argia johannella, sp.n. (Tab. X. figg. 12, 12s, 19.) 
g. Rear of the head black, with a pale stripe along each eye-margin, wider superiorly. Pale (blue or 
violet) antehumeral stripe three-fi'ths to four-fifths as wide as the black mid-dursal thoracic stripe. 
