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 descril)cd a re- 

 markable species of crane-fly as Tipida 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 moniliformis, a 

 second form distinguished from Loew's species by th(^ much 

 lighter (yellow) ground-color of the wings and other characters. 

 In 1891, the third species, ornaticornis, was described by "\"an 

 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 

 exilis sp. n. and jivaro sp. n., and the following Hues 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 base, 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 R2 to 



31 Stett. Ent. Zeit., xlvii, p. 259. 



32Tijd. voor Entomol, xxxiv., p. 195, pi. 12, figs. 1, 2. 



TRANS. ENT. AM. SOC, XLII. 



