STREPSIPTERA. 291 
appendages being much more analogous to the labial palpi of the 
Lepidoptera, than to the maxillary palpi of the Diptera. (Comp. 
Curtis, 24, f. 6. Gastropacha; or 328. f. 3, 4, Ptilophora.) 
The antenne are of singular construction, although consisting of but 
afew joints: they arise between the front of the eyes near the base 
of the contracted ocular foot-stalks. The basal joint is thick, and 
enlarged to the tip; the second joint small, or of moderate size. In 
Stylops the antenne are furcate, the third joint being produced, on the 
outside below, into an elongated flattened plate nearly as long as the 
remainder of the antennz: the fourth joint is inserted near the base 
of this plate, on its upper side * ; it is rather depressed, and about half 
as long as the third joint: the fifth and sixth joints are still shorter and 
more slender (fig. 93. 5.). In Elenchus (jig. 94.1. and 6. side of 
the front of the body, showing the antennz and pseudelytron, after 
Curtis) the antenne are also furcate after the second joint, but the third 
joint is much more slender and elongated than in Stylops; and there 
only appear to be two other joints, which are also more elongated and 
slenderer. In Xenos (jig. 94. 12.) the furcations of the antenne (after 
the second joint) are nearly of equal size, the third joint emitting from 
its base a single-jointed branch; so that, in this genus, these organs are 
apparently only 4-jointed. In Halictophagus (fig. 94. 7.) the antennze 
are more regularly constructed; consisting of seven joints, those after 
the second joint being flabellated, each (except the last, which is 
elongated) emitting a thickened branch. Mr. Kirby noticed the 
analogy which existed between the antenne of some of these in- 
sects and many Coleoptera and Hymenoptera, which have branching 
or furcate antenne. But it is tobe observed, that, with the exception 
of a very few (Gyrinus, Parnus), antennz thus constructed are found 
only amongst male insects; and hence it appears to me not impro- 
bable that all the winged individuals of this order, yet discovered, are 
males+, all exhibiting a complicated structure in their antenne: this 
is especially the case with Halictophagus. 
The thorax is very large, oblong, and singularly developed, con- 
* Mr. Kirby describes the third and fourth joints as both arising from the 
preceding. 
+ Professor Peck considered that all his specimens of X. Peckii, which were alike, 
were males (Linn. Trans. vol. xi. p. 91.) ; but Mr. Kirby, chiefly regarding the 
anal appendages as an oviduct, apprehended that they were females. Rossi states 
that he was acquainted with both sexes of Xenos, but Jurine doubts this. All the 
specimens reared by the latter (as many as twenty) were exactly alike. 
i 
