G. F. Ferris and F. R. Cole 181 . 
cleared specimens; in the chaetotaxy of the head and thorax; in the form of 
the first abdominal sternite and in the form and arrangement of the tergal 
plates of the abdomen. There is evidently a certain amount of variation in 
the chaetotaxy but not enough to be especially disturbing. The presence or 
absence of an apical seta or setae on certain of the tibiae is evidently a valuable 
specific character in some instances. 
The volant individuals, that is those taken before the wings have been 
dropped, differ so markedly from those that have dropped the wings and 
become distended by full feeding that at first difficulty was experienced in 
correlating the two forms. The abdomen in the volant individuals is so small 
and contracted that the distribution of the setae can not be determined with 
accuracy. The tergal plates are not entirely defined, the diverging dorsal lines 
seen in L. depressa , for instance, not appearing at all. Reference to the 
chaetotaxy of the head and thorax, however, has been sufficient to permit 
the definite placing of all examples of this sort that we have seen. 
Sexual dimorphism. 
In pinned specimens of the ordinary type it is very difficult to distinguish 
between the sexes, in fact most authors appear not to have attempted any 
such distinction. It seems to have been supposed by some that the males 
retain the wings. Massonat (1909, p. 59) has pointed out that this is a mistake 
and we are entirely in accord with his views, for, in our material of L. depressa 
and L. subulata , both sexes appear without the wings. It is probable that this 
mistake has arisen simply from a failure to distinguish the sexes. Correlated 
with this error, some authors appear to have thought that the slender-bodied 
volant individuals must be males. For example, one such individual received, 
through the kindness of Major Austen and by him labelled as a male, is in 
reality a female. 
It is true that in the male the abdomen appears never to attain the size 
that it does in the female, but otherwise there is little but the presence of the 
genitalia by which to distinguish them, at least in all the species we have 
examined except L. cervi. We have not seen the male of this species, but 
according to Massonat there is a decided difference in the form and arrange¬ 
ment of the abdominal plates. The external genitalia of the males at the most 
consist of a pair of small, ventral processes, and in some of the species even 
these are lacking. The internal structures show very plainly in cleared specimens 
and permit no possibility of error as to the sex. 
Larvae. 
Larvae of two species, L. depressa and L. mazamae , were found within 
the bodies of females. The number of specimens (one of each species) is not 
sufficient to permit any extensive study. Nevertheless, certain interesting 
facts are revealed. 
