ERISTALIS. 65 



reddish-yellow ; first two joints blaekish. Mesonotum opaqne Uaek, mth three complete ashy bands 

 Scutellum black, with a rounded ycllow spot at the apex (variable ?). Pleurte ashy-pollinose. Abdomen 

 opaque black ; a narrow, interrupted or entire, band on the third and fourth segments, shining ; second 

 segment with two oval spots, broadly separated ; the anterior angles of the third segment, and the 

 narrow hmd margins of the second, third, and fourth segments, yellow. Legs black; base of the four 

 antenor tibiae, and the base of the middle tarsi, yellow ; hind femora much thickened. Wings hyaline. 

 Front moderately narrowed above, with an opaque black band below the middle, narrowly extending 

 down a short distance in the centre. Fifth abdominal segment like the fourth. 

 Length 6-7 millim. 



Hab. Mexico, Teapa in Tabasco (II. H. Smith). 



Five specimens. 



In only one of the three females is the scutellum as in the males ; in the others it is 

 yellow, with the base narrowly black. This female vvith the scutellum like that of the 

 males has no yellow on the anterior angles of the third abdominal segment. The 

 front tarsi may be yellowish at the base. From E. pusio and E. pygmceus, the species 

 may be easily distinguished by the incrassate hind femora. 



20. Eristalis rufiventris. 



Eristalis rvfiventris, Macq. Dipt. Exot. 1« Suppl. p. 129 1 ; Willist. Trans. Ara. Ent Soc xv 

 p. 282 \ 



Hah. Mexico, Teapa in Tabasco (H. II. Smith). —8o\jtk Ameeica, Colombia \ 

 Brazil * 



A number of examples, both male and female, agree so well in every respect, save 

 in the colour of the second abdominal segment, with a male specimen from Brazil 

 identified as E. rufiventris, that I believe they belong to the same species. The 

 second segment does not have a distinct black interval in the middle, but is narrowly 

 brownish. 



21. Eristalis 



Hab. Mexico, Teapa and Frontera in Tabasco H. Smith). 

 One hundred and twenty specimens. 



It is not at all impossible that this species has been described, but, belonging as it 

 does to a very difficult group, I cannot identify it. It has three ashy thoracic bands, 

 separated by opaque black ; the antenme yellowish-red ; the frontal triangle with 

 black pile. The abdomen in the male is red or yellowish-red, the second segment 

 with an opaque black stripe, expanded posteriorly, the third and fourth segments with 

 a narrow shining band, that of the third often obsolete ; the hypopygium shining 

 black. In the female, the third and fourth abdominal segments are black in the 

 middle, and, sometimes, behind. The hind femora are only a little thickened. 

 Length 8-10 millim. 



biol. centr.-amer., Dipt., Vol. III., February 1892. 



k 



