ISCHNURA. 129 
dorsal; abdomen largely orange, becoming yellowish posteriorly, with the following dark metallic green 
parts on the dorsum—a basal spot on segment 1; a median line on 2, having an anteapical transverse 
line across it; a median line on 3, except at base, expanded into a wide spot on the apical fourth; a 
broad mid-dorsal stripe on 4-7 (except for the basal tenth or twelfth, which remains yellow), more or 
less constricted at three-fourths the length of the segment, and subsequently widened ; a stripe each side 
of 8, the two confluent in basal third, or for most or all of the segment; a spot each side of 9 in 
basal half. 
Some females which appear to be intermediate between the black and orange specimens differ from the latter 
as follows :—postocular spots blue, isolated pale prothoracic spots sometimes absent, humeral stripe wider, 
segments 2 and 3 marked similarly to 4—7. 
A number of females, evidently more aged and having some pruinosity, have the entire dorsal surface of the 
thorax and abdomen obscure, blackish. In some of these it is possible to trace the outline of postocular 
spots similar to those of orange females, and confluent with the pale colouring of the rear of the head. 
In others, the postocular spots have entirely disappeared ; judging from analogy with J. verticals, Say, 
of the eastern United States, these latter may have been either of the black or of the orange form. 
An examination of 46 females gives 44 without any vulvar spine, 1 (Acambaro) with an extremely small 
spine, 1 (Missoula, if it really be of this species) with a small spine. 
The pterostigma of the hind wings is not infrequently markedly smaller than that of the front wings in this 
sex also, although of similar shape and colour. 
Postcubitals: ¢ front wings 8-6, majority with 7; hind wings 7-5, majority with 6. 2 front wings 10-8, 
9 and 8 of equal frequency ; hind wings 7—6, majority with 7. These figures, based on thirty individuals, 
are in accord with the conditions found in the other species of Ischnura here treated. 
Dimensions :— Arizona. Durango. | Acambaro. 
mm. mm. mm. 
Abdomen ¢...... se eens 18:5-21 18°5-20 18-21 
black @ ............ vee 19 eee 
orange 2 .........6.. 18°5-21°5 20 19-21 
Hind wing ¢ ............ 11:5-13 11-12 12°5-14 
black 9 .........05. Lae 15 a 
orange 9 ........0-.. 13-15°5 15 14-15 
Hab. Unrrep States, Missoula, Montana (Elrod: 1 2); Denver, Colorado (Beales : 
1 @); Santa Fé and Lone Mt. [Cockerell: 1 ¢, 1 9 *|, Faywood [W. J. Gerhard: 
lor. 9], New Mexico; Tucson [Kunze: 5 g,1 9] (coll. P. P.C.); Arizona (M,C. Z., 
C. U. lot 35: 10 g, lor. 2,6 2, see footnote, p. 104).—Mexico, Durango (Barrett, 
coll. P. P. C.: 4.3, lor. 2, 1bl. 2, 8 2), Aguas Calientes (LZ. 0. Howard, U. 8. 
N. M.: 14,12), Acambaro [22 ¢, 6 or. 2,17 9], Morelia! ?, Patzcuaro [1 ¢ 
1 or. 2] (Rhoads), Tacuba (Barrett, coll. McLachlan: 1 2), Mexico city (Barrett, 
colls. Adams, P. P.C.: 2 6,1 2). 
In the United States April to July; in Mexico March (Acambaro), October 
(Durango), December (Mexico city). 
The identification of the female from Montana is rather doubtful; it inclines toward 
I. perparva, the male of which I have from the same locality and date. 
The females of [. demorsa are very much like those of J. verticalis, Say ; the latter 
has a flatter prothorax, evident in the shape of the hind margin, which is almost 
* In this list unquestionably orange and black females are mentioned as “or. 2” and bl. 2 ” respectively ; ; 
older females, which may have been either, are simply enumerated as “ 9.” 
BIOL. CENTR.-AMER., Neuropt., February 1903. | . Ss 
