20 DIPTERA. 



J * 



2. Allograpta fracta. x 



Allograptafracta, Osten Sacken, Western Diptera, in Bnll. U.S. Geol.&Geogr. Snry. m. p. 831. ; 



Willist. Synopsis-N.-Am. Syrphidse, p. 97 \ 

 lAllograpta exotica, v. d. Wulp, Tijdsehr. v. Ent. xxvi. p. 2, t. 1. f. 2 3 (nec Wiedem. ?) . 



Hab. Umited States, California 1 2 .— Mexico, Xucumanatlan 7000 feet, Venta de 

 Zopilote 2800 feet, both in Guerrero (H. H. Smith), Ciudad in Durango (Forrer).— 

 Antilles, Guadaloupe 3 . 



Four specimens from Mexico, differing chiefiy from A. obliqua in the presence of a 

 deep black facial stripe. The first abdominal segment is as in A. obliqua, and the 

 band of the second segment is not interrupted. 



3. Allograpta ? 



? Syrphus exoticus, Wiedem. Anssereur. zweifl. Ins. ii. p. 136 l . 



Hab. Mexico, Xucumanatlan 7000 feet, Omilteme 8000 feet, Amula 6000 feet 

 (H. H. Smith).—BnAziL K 



Differs markedly from the two preceding species in the mesonotum being opaque 

 dark green in both sexes. The black stripe of the face is broader than in A. fracta, 

 the hind legs and abdomen darker. The third joint of the antennae is largely black. 

 Four specimens. 



SPH^KOPHOE-IA. 

 Sphcerophoria, St.-Fargeau & Serville, Encycl. Mdthod. x. p. 513 (1825). 

 Melithreptus, Loew, in Oken's Isis, 1840, p. 573. 



The genus Sj)hwrophoria is, at present, one of much difhculty, iuasmuch as it 

 requires often numerous specimens, from different localities, to determine the limits of 

 variational differences. The black markings of the face and front, ancl of the legs, and 

 the markings of the abdomen are all more or less variable, and one should not place 

 too much dependence upon them. All the species which I have so far seen from 

 Central America have a small hypopygium and incomplete lateral thoracic stnpes. 

 Bigot has, however, described species with the normal hypopygium. Even where 

 the hypopygium is minute, one can scarcely mistake the generic relationships, as 

 presented in the structure of the head and face, and the elongate abdomen. 



Synopsis of the recognized Central-American sjjecies. 



1. Fifth segment of the abdomen with four elongated spots or stripes. 2. 

 Eifth segment of the abdomen with a transverse band .... 4. 



2. Fourth abdominal segment with an uninterrupted arcuate yellow 



band 3. 



Fourth abdominal segment with rectangular ancloblique markings. Sp. (no. 3j. 



