66 



DIPTEEA. 



There are also the following described species from within our limits :— 

 Eristalis diminutus, Walk. List Diptera, iii. p. 622.— Mexico. 



expictus, Walk. Trans. Ent. Soc. Lond. new ser. v. p. 290.— Mexico. 



familiaris, Walk. loc. cit. — Mexico. 



mexicanus, Macq. Dipt. Exot. 2 e Suppl. p. 75.— Mexico. 



fulvipes, Bigot, Ann. Soc. Ent. Fr. 1880, p. 225.— Mexico. 



sackenis, Bigot, loc. cit. p. 224. — Mexico. 



LYCASTRIRHYNCHA. 

 Lycastrirhyncha, Bigot, Rev. et Mag. Zool. 1859, p. 307. 



1. Lycastrirhyncha nitens. 



? Lycastrirhyncha nitens, Bigot, Rev. et Mag. Zool. 1859, p. 307 l . 



Hab. Mexico, Vera Cruz (H. H. SmUIij—SoVTR Ameeica, Amazons l . 



This very peculiar Eristalid is, I believe, entitled to generic rank. The epistoma is 

 produced into a conical, elongate snout, quite like that of Rhingia. The male is 

 dichoptic and the hind femora are thickened. The eyes are bare. As the diagnosis 

 given by Bigot is inadequate to determine the species with certainty, I here give a 

 brief description of our specimens : — 



Male. Face thickly yellowish-dusted, in the middle and on the upper part of the snout metallic hlack. 

 Antennse red. Front opaque hlack across the middle, shining above and helow. Mesonotum metallic 

 hluish-black, with a broad, interrupted, lateral, posteriorly geminate stripe, and four slender median 

 stripes, coalescent in two pairs posteriorly, opaque black. Scutollum opaque black at the base, the apex 

 shining. Abdomen opaque black ; a spot on the posterior margin of the third segment, and the 

 cylindrical fourth segment, except three equidistant round opaque black spots, and the hypopygium, 

 shining metallic ; second segment on each side with a large, the third with a smaller, spot, yellow. 

 Legs black ; knees, base of femora, and middle metatarsi yellow. Wings hyaline. 



Ftmale. Front on each side with an opaque spot. Third, fourth, and fifth abdominal segments shining 

 metallic, the two former each with three equidistant opaque black spots and a narrow yellow hind 

 margin. 



Length, including snout, 8-9 milliin. 



This description, it will be seen, differs materially from Bigot's diagnosis ; but it 

 will be time enough to name our form when its specific distinction shall be shown. 



PTEROPTILA. 



Plagiocera, Macquart, Dipt. Exot. ii. 2, p. 59 (1842) (nec Klug). 

 Pteroptila, Loew, Centur. vi. no. 59, in Berl. ent. Zeitschr. 1865, p. 165. 



l. Pteroptila crucigera. 



Milesia acuta, Fabr. Syst. Antl. p. 189 1 ; Wiedem. Aussereur. zweifl. Ins. ii. p. 110 (translation 

 from Fabricius) 2 . 



