CHARLES P. ALEXANDER 23 
One female from Lima, Peru, altitude 500 feet, taken on 
August 21, 1914, by Parish. 
The Monilifera Group, 
In Linnaea Entomologica for 1851, Dr. Loew described a re- 
markable species of crane-fly as Tijmla monilifera n. sp. This 
insect came from Rio de Janeiro, Brazil, and was indicated as 
being notable by the beautiful wing-pattern and the interesting 
structure of the antennae in the male sex. In 1886 von Roder^^ 
described from Ecuador, under the name of monUiformis, a 
second form distinguished from Loew's species by the much 
lighter (yellow) ground-color of the wings and other characters. 
In 1891, the third species, ornaticoriiis, was described by Van 
der Wulp,^- his type coming from Colombia. 
The group is very well represented in collections received from 
South and Middle America, especially from the Andean region, 
and in the present account the author has endeavored to give 
his opinions concerning the status of the group. From the great 
variation in the specimens it is easily understood that we are 
here not only dealing with numerous forms that are closely re- 
lated to one another, but also with species which show a con- 
siderable degree of variability in color-pattern. 
It appears that the group has been derived from forms such as 
exilic sp. n. and jivaro sp. n., and the following lines of specializa- 
tion seem to have been followed: the antennae, from the short, 
normal Tipuline organ with the flagellar segments enlarged-oval 
at the base and slightly and gradually constricted about mid- 
length, have gradually evolved into the slender, graceful antenna 
which in the more specialized forms {monilifera Loew, monili- 
formis Roder, armillatus sp. n.) is nearly as long as the entire 
body; in these forms the ten apical flagellar segments are en- 
larged-rounded at the liase, abruptly constricted into a long, 
slender, uniform pedicel beyond, producing the nodulose, bead- 
like effect that is so conspicuous in these insects. Evolution 
in the wing-venation is not so apparent, as might well be expected 
in this remarkably homogeneous genus of flies; however, the 
slight shortening of the radial sector and the tendency of Ro to 
31 Stett. Ent. Zeit., xlvii, p. 2.59. 
'^Tijd. voor Entomol., xxxiv., p. 195, pi. 12, figs. 1, 2. 
TRANS. ENT. AM. SOC, XLII. 
