1909] JOHNSON — FRAX 39 
ERAX RUFIBARBIS (Macquart). 
Asilus aestuans Wiedemann, Dipt. Exot. p. 200, 1820 (non Linné). 
Erax rufibarbis Macq., Dipt. Exot., I, pt. 2, 116, 1839. 
The A. aestuans of Wiedemann is a very different species from what Linné 
described. ‘ Rubido-fuscus, * * barba et vibrissae rufo-flavicantes, * * mare abdomi- 
nis segmentis duabus penultimis albis’” seem only referable to the species common 
in late summer and early autumn, and later described by Macquart as LE. rufibarbis: 
“Mystace rufo. Abdominis segmentis duobus apicalibus albis.” Macquart noticed 
the discrepancy between Linné’s and Wiedemann’s description (Hist. Nat. Dipt., I, 
312, 1834) and described Linné’s species, but in 1838 (Dipt. Exot., I, pt. 2) he seems to 
have forgotten or ignored the fact and gives Wiedemann’s description of [. aestuans 
on page 115 and on page 116 describes his E. rufibarbis. Since Dr. Williston in 1885 
(Trans. Amer. Ent. Soc., XII, 72) referred to the above synonymy, there has 
been no change. As Wiedemann’s name cannot be used, we are obliged to adopt 
the one given by Macquart. 
ERAX ALBIBARBIS Macquart. 
E. albibarbis Macq., Dipt. Exot., I, pt. 2, 118, 1838. 
E. cinerescens Bellardi, Saggio Ditt. Mess., pt. II, 39, pl. 2, f. 10, 1861. 
E. furax Williston, Trans. Amer. Ent. Soc., XII, 67, 1885. 
There seems to be no doubt regarding the synonymy of this common and widely 
distributed species, and Macquart’s name will have to be adopted. 
ERAX INTERRUPTUS (Macquart). 
Asilus interruptus Macq., Hist. Nat. Dipt., I, 310, 1834. 
Erax maculatus Macq., Dipt. Exot., I, pt. 2, II, pl. 9, f. 6, 1888. 
Erax lateralis Macq., Dipt. Exot., I, pt. 2, 116, 1838. 
Erax ambiguus Macq., Dipt. Exot., Suppl. 1, 84, 1846. 
Erax (Eristicus) villosus ‘Bellardi, Saggio, Ditt. Mess., pt. I, 49, 1861. 
Neoeristicus villosus (Bellardi) Osten Sacken, Cat. Dipts Nev AL, 1878; p. Sih 
(Note 129, p. 235. Hristicus preoccupied). 
The above synonymy is practically that given by Osten Sacken. After a careful 
study of the descriptions Macquart’s oldest name has been given precedence. 
