60 



DIPTEKA. 



4. Eristalis pachypoda. 



Eristalis pachypoda, Bigot, Ann. Soc. Ent. Er. 1880, p. 224 \ 



Hab. Mexico 1 ; Costa Kica, Volcan de Irazu 6000 to 7000 feet, San Francisco 

 4500 feet* Cache (Rogers). 



It is impossible to say with certainty whether this or the preceding species is the 

 one described by Bigot, as his description applies about equally well to both. The 

 present one difFers from E. obsoletus, in the male sex, in the frontal and vertical 

 triangles being black-, not yellow-, pilose ; in the broader, more deeply black abdomen, 

 clothed chiefly with black, not yellow pile ; in the rather darker legs, larger size, and 

 more distinct brown spot on the wings. The females may be best distinguished by the 

 pile of the front being mostly black in R pachyjwda, light yellow in E. ohsoletus. 



5. Eristalis latifrons. 



Eristalis latifrons, Loew, Centur. vi. no. 65, in Berl. ent. Zeitschr. 1865, p. 169 1 ; Willist. 



Synopsis N.-Am. Syrphidse, p. 164 2 . 

 Eristalis stipator, Osten Sacken, Western Dipt., in Bull. U.S. Geol. & Geogr. Survey, iii. p. 336 3 ; 



Willist. Proc. Am. Phil. Soc. xx. pp. 319, 322 4 . 

 Hab. United States, Kansas 2 4 , Colorado 2 3 4 , New Mexico 2 3 4 , Arizona 2 , Texas 2 , 

 Califoraia 2 3 4 .— Mexico, Matamoros (Osten Sacken 1 ), Northern Sonora (Morrison), 

 Amula iu Guerrero (H. H. Smith). 



Twenty specimens, agreeing well with northern ones. 



6. Eristalis ochraceus. 



Eristalis ochraceus, Willist. Trans. Am. Ent. Soc. xv. p. 279 \ 



Hab. Mexico, Teapa in Tabasco (H H Smith). — Soutii America, Brazil K 



A single female example from Teapa agrees well with a type-specimen from Brazil. 

 The pile of the thorax is very short. The abdomen is red, each segraentwith a slender 

 black band preceding the narrow yellow hind margin ; the fifth segment is shining 

 black, except the anterior margin, which is opaque grey, like the first segment; the 

 second segment has a lateral triangle, the third and fourth a complete band, shining. 



7. Eristalis Mlardi. 



? Eristalis bogotensis, Macq. Dipt. Exot. ii. 2, p. 52 \ 



Eristalis bellardii, Jaennicke, Neue exot. Dipt., in Abh. Senck. Ges. vi. p. 400 \ 

 Eristalis rufoscutata, Bigot, Ann. Soc. Ent. Fr. 1880, p. 221 3 . 



Hab. Mexico 23 , Ciudad in Durango (Forrer). — Colombia, Bogota *. 

 Twelve specimens. 



These vary in length from less than 10 to 13 millim. The third segment of the 



