23 
the three first fanicle joints is about doable the length of the pedicel, and the throe 
following decrease in length until the sixth is scarcely twice as long as thick : the 
club is slightly broader than the funicle, is rounded on the end. and is ai long as the 
last two funicle joints together. The facial impression is small, and the forehead ex- 
tends ue ar 3 the lower end of the eyes : the vertex is broad, and the ocelli are at 
the corners of an equilateral tri.v ' ■ both clypus and vertex are very finely punc- 
tured. The thorax is moderately arched, the rnesonotum somewhat shining and finely 
shagreened with sparse hair follicles: the scapula- meet in the middle and forma 
very short longitudinal carina : the triangular, finely wrinkled scutellum has rattier 
sharp side borders and apex. The upper side of the abdomen is very delicately punc- 
tured and the segments are difficult to distinguish : seen from the side they appear 
subequal in length. The marginal vein of the fore wing is somewhat longer than 
th^ stigmal, which is nearly equal in length to the postmarginal. The ovipositor 
is usually considerably protruded. The legs are longer than usual, and the middle 
tibial spur is very strong and prominent. 
Male. — The male is to be principally distinguished by its autenn;e, which are con- 
siderably longer than the whole body. The relative proportion of the joints is about 
the same as in the female, except that the pedicel is very conical and only about as 
long as thick ; the funicle joints are well separated by dorsal incisions, and each is 
very slightly constricted in the middle above : the funicle is furnished with a num- 
ber of long hairs, which are not arranged in whorls. 
This striking genus was founded by Forsterin 1852, and in the char- 
acterization of the female I have followed Mayr quite closely. Dr. 
Mayr. however, had before him but one specimen ( $ ), and as my ma- 
terial is extensive, I have made one or two changes. I have added a 
description of the male which was unknown to both Forster and Mayr. 
The geuus was founded on antennal characters, but may be recognized 
at a glance from the length and strength of the middle legs. 
36. (1) Leptomastix dactylopii. n. sp. 
Female.- Length, 1.51 mm ; expanse, 3.6 mm ; greatest width of fore wing, 0.6 mm . Gen- 
eral color honey-yellow, with a slight reddish tinge on the meaonotnm : eyes, anten- 
na* (with the exception of a slight ventral yellow streak ). occiput, immediately behind 
the eyes, black; metascutum, posterior margin of pronotum. dorsum of abd< 
dorsal surface of posterior femora, more or less dusky. 
Male.— Length, 0.9?""" : expanse, 2.65™™ : greatest width of tore wing. 0.46" : ". In 
effect darker than female, and quite variable in the amount of black with which the 
dorsum of the thorax is ornamented. The mesoscutum is always yellow, but the 
scapulae are often very dark and the mesoscntellnm has often a dark median stripe: 
the hind tibia* and tarsi are also dark. 
This species is described from many specimens of both sexes bred iu 
October and November, 1684, from Dactylopius destructor Comst, infest- 
ing Paeonia on the Department grounds at Washington, l>. C, in com- 
pany with Ghiloneurus dactylopii. It is very similar to Leptomastix his- 
trio, judging from Mavr's description of the latter, and the dilVerenee 
may arise from the fact that kistrio was described from a single speei- 
