260 HEMIPTERA-HETEROPTERA. 
The types of Stal’s species are before me, and, with our long series of specimens for 
comparison, it is evident that they are forms of one variable insect. In the typical 
Z. exsanguis the posterior lobe of the pronotum is flattened on the disc and considerably 
dilated at the sides, and the lateral spines are pale and directed outwards. In Z. luridus 
the lateral spines of the pronotum are black, and the pronotum is narrower at the 
base. In Z. ambulans the apices of the femora are black, a character of no importance 
as the knees are often darker in Z. exsanguis ; and the lateral spines of the pronotum 
are usually infuscate or black, these being in some specimens directed forwards 
(Z. cognatus, Costa) and in others outwards. The pronotum often has a transverse 
row of four or five dots between the two lobes, and the tuberculiform anterior angles, 
black ; the lateral spines vary in length. The two basal joints of the antenne are 
testaceous or reddish, with the apex infuscate or black; the first joint varies in length. 
The males have the third antennal joint thickened to about the middle, and the 
terminal genital segment armed at the apex with a stout, tapering, upwardly-curved 
spine. The hind tibie are simple in both sexes. The very variable Z. chameleon, 
Stal, from Colombia, is an allied form. A female of Z. exsanguis from El Tumbador 
is figured. 
14. Zelus levicollis, n. sp. (Tab. XV. fig. 24, 2.) 
Q. Elongate, narrow, moderately robust, shining, sparsely pubescent, stramineous; the head with the 
post-ocular portion black above, a line on each side extending from the eyes to the ocelli, and also one 
down the middle, stramineous, the anterior portion mottled with brownish ; the pronotum dilute fuscous, 
with the lateral and basal margins, and two transverse rows of small spots on the anterior lobe, 
stramineous ; the elytra fuscous, with the costal and median nervures of the corium, as well as the 
portion of the latter adjoining the base of the membrane, stramineous, the membrane smoky ; (antenne 
broken off). Head elongate, gradually narrowing behind the eyes, the basal portion stout and cylindrical. 
Pronotum a little longer than the head; the anterior angles armed with a short stout tooth, the lateral 
augles with a very short tooth; the anterior lobe sulcate down the middle, with sinuous lines of 
pubescence between the smooth bare spots; the posterior lobe flattened on the disc and with indications 
of two anteriorly converging carine in front, apparently smooth, but with a close minute punctuation 
showing through from beneath. Scutellum blunt and thickened at the apex. Legs sparsely pilose, 
moderately elongate; the anterior femora as long as, but much stouter than, the hind femora; the hind 
tibiz simple. 
Length 133, breadth of the pronotum 24 millim. 
Hab. Mexico, Milpas in Durango 5900 feet (Forrer). 
One example. This species is nearest allied to Z. exsanguis, var. luridus, St&l, but 
differs from it in having the posterior lobe of the pronotum almost smooth, with the 
lateral angles armed with a very short tooth, and the legs less elongate. From 
Z. janus (¢), which it resembles in the arrangement of the pubescence on the anterior 
lobe of the pronotum, it may be separated by the simple posterior tibie, the much 
smaller size, narrower shape, &c. 
