FAM. EMPIDID/E 377 
Type species ; P. claripennis, Melander, the only species known. Many specimens of this 
Insect were taken by Mr. H. L. Viereck in r9o2 at Alamogordo, New Mexico, at which time and 
place he took also the two species of the recently described genus Cenoetus Cole.  Cenotus, which is 
strikingly like Prorates, although generically quite distinct, was assigned by Cole to the Therevidz, 
in which family it is aberrant in lacking the « small crossvein » at the apex of the second basal cell and 
in being bristleless. 
Prorates has been regarded asa primitive but anomalous Empid. . Judging by the structure of its 
proboscis it probably is anthophilous. In appearance it suggests a minute Therevid or Bombyliid with 
reduced neuration, or a Scenopinid. According to existing tabulations to the families of Diptera the 
species would be located in the Empididz in the subfamily Hybotina. From all the members of 
this group, however, it departs in having the costa stopping at the third vein, the auxiliary vein distinct 
and ending in the costa, the antennal style microscopic, and the mesopleure furnished with some 
pubescence. 
Meghyperus, which is more clearly Hybotine than Prorates is, shows many parallel characters, 
such as the distinct though evanescent auxiliary vein, presence of alula, dichopticism of female, and 
bristleless legs. These important characters, all at variance with other Hybotinz, perhaps indicate 
primitive traits retained from a common ancestor, but more likely are the result of a parallel evolution 
among insects having similar flower-frequenting habits. 
It is not yet time to remove MegAyferus from the Hybotinz, but Prorates may properly be 
placed in the Bombyliide, where with Ma//Zacotricha (—  Heterotropus) and also with Cemotus it will 
comprise the subfamily Heterotropine. The three genera may be separated as follows : 
I. Proboscis forrect ; first. basal cell much longer than ihesecond. ^... 2. 02 ooo oo UR. 
Proboscis very short, not projecting ; first basal cell not greatly longer than (he 
SONORO Uu Ie P LORI C MIU EIE dea md rs NJenus CAENOTUS, Cole; 
2. Pygidium deeper than long ; discal cell wider than the second basal, emittiug 
three posterior veins ; third autennal joint subulate, with bristle-lipped style. Genus HgrEROTROPUS, Loew. 
Pygidium longer than deep ; discal cell narrower than the second basal, fourth 
vein peliolate; third antennal joint conical, with microscopic style . . . Genus PmomRarES, Melander. 
Geographical distribution. 
I. P. claripennis, Melander, Ent. News Philad. Vol. 17, p. 373, f. (1906); New Mexico. 
Williston's Man. N. Amer. Dipt. p. 219, f. 5 (1908). 
ADDENDA : RECENTLY DESCRIBED EMPIDIDZE 
GENUS ACARTERUS, Loksw 
A. varies, Senior- White, Spol. Zeylan. Colombo, Vol. 12, p. 394 (1924). Ceylon. 
GENUS ARIASELLA, GiL 
Ariasella, Gil, Bol. Soc. Esp. Hist. Nat. Vol. 23, p. 151 (1923) (1). 
A. semiaplera, Gil, Bol. Soc. Esp. Hist. Nat. Vol. 23, p. 151, figs. (1923). Spain. 
(1) Ariasella, a genus related to Piel/ainia, Arias, but characterized by having vestigial wings. Type 4. semiaftera, 
Gil, a species slightly under three millimeters in length. Thorax compressed, body blackish, legs especially the hind 
femora and tibize, robust, one notopleural, two scutellar bristles; face narrow, one pair ocellar bristles, third antennal joint 
circular, with dorsal arista; wings vestigial, reaching the fifth abdominal segment, the basal two-thirds consisting of a 
strap-like pedicel, with only the costal and a single longitudinal vein; halteres absent. 
