148 INSECUTOR INSCITIj^ MENSTRUUS 



slopes to 1 4,000 feet and even higher, but are especiaJly prolific in forms 

 between 4,500 and 9,500 feet, and most of all so on the eastern slopes 

 at 6,500 to 7,500 feet or about the limits of forest growth, the increase 

 of altitude depending on approach to the equator and the figures given 

 applying from southern Peru to southern Ecuador. The superficially 

 similar tribes Epalpini of the Hystriciidae and G^mnommini of the 

 Pyrrhosiinae appear to come first with respect to prolificness in forms. 

 The most unlooked-for variety of these flies especially, but also of various 

 Hystriciid forms, was found by me at Uruhuasi, in southern Peru, at 

 about 6,500 feet; near Huacapistana, in central Peru, at about 6,700 

 feet ; on the east base of Huascaray, in northern Peru, at about 7,000 

 feet; and at Manchi, in southern Ecuador, between 7,000 and 7,500 

 feet. By far the greater part of the descriptions in this paper cire of forms 

 of these flies found by me at Uruhuasi and Huascaray. Many others 

 were found in the high puna region extending from Lake Junin to Lake 

 Titicaca, and down the Rimac Canyon on the western slopes to Matu- 

 cana and Agua de Verrugas, the latter being 5,000 feet. Some of 

 these have already been described (Proc. U. S. Nat. Mus., vol. 43, 

 no. 1935 ; Psyche, June, 1913), and a few more are included in this 

 paper. 



On epistomal, macrochaetaJ, palpal characters zmd general habitus, the 

 Epalpini in large part approach closely to many of the Gymnommini, 

 but the uterine characters seem to indicate that the two stocks are quite 

 distinct and that the similarity in external adult characters is due to par- 

 allelism rather than to close relationship. The same conditions occur in 

 other muscoid stocks, as witness the remarkable external similarity in Sisy- 

 Topa hemerocampae Y. of the Exoristidae and Eumasicera coccidella T. 

 of the Masiceratidae, whose close relationship is positively contradicted 

 by the uterine and egg characters as well as those of the maggot. Some 

 of the Pyrrhosiinae possess a colored maggot and some are furnished 

 with spine-like macrochaetae. Tropidopsis, Janthinom^ia, and Para- 

 gymnomma are examples of the latter category ; while Eugymnochaeta, 

 G^mnochaetopsis, Macquartia, Sieiniella, and others are examples of 

 the former. Recently the writer has found forms with both colored mag- 

 gots and spine-like macrochaetae. 



(To b,e continued.) 



Date of publication, November 29, 1913. 



