56 DIPTERA. 



yellow; distinctly clouded distally. Legs light yellow ; the immediate base of the femora hrownish; 

 front and middle tibise, except their base, and their tarsi, black, the corresponding parts of the hind legs 

 more brown. 

 Length 9 millim. 



Hab. Mexico. Acaguizotla in Guerrero (H. H. Smith). 

 Two specimens. 



COPESTYLUM. 



Copestylum, Macquart, Dipt. Exot. l er Suppl. p. 124 (1846). 



1. Copestylum marginatum. 



Volucella marginata, Say, Journ. Acad. Phil. vi. p. 167 1 ; Complete Writings, ii. p. 360 2 j Osten 

 Sacken, Western Diptera, in Bull. U.S. Geol. & Geogr. Survey, iii. p. 333 \ 



Copestylum marginatum, Osten Sacken, Cat. N.-Am. Dipt. 2nd ed. p. 130 4 ; Willist. Synopsis N.-Am. 

 Syrphidse, p. 151, t. 7. figg. 1, 1 a, 1 b 5 . 



Copestylumflaviventris, Macq. Dipt. Exot. l er Suppl. p. 125, t. 10. f. 16 6 . 



Hab. United States, Texas 3 4 5 , Arizona 5 , California 5 , Montana 5 , Colorado. — 

 Mexico 124 , Northern Sonora (Morrison), Tepetlapa in Guerrero (H. H. Smith) ; 

 Guatemala, San Geronimo (Champion). — South America, Colombia 6 , Yenezuela 6 . 



Central-American specimens are of the variety with light antennse, as described by 

 me, and show no differences from the description, and only minor differences among 

 themselves. 



2. Copestylum limbipenne. (Tab. II. figg. 2, $ ; 2 «, head ; 2 b, antenna.) 



Copestylum limbipennis, Willist. Synopsis N.-Am. Syrpliidae, p. 152 K 

 Hab. Mexico, Yenta de Zopilote, Acapulco (H. H. Smith), Isthmus of Tehuantepec u 



The females agree with the description ; the antennae are somewhat lighter 

 coloured, and the lateral margins of the abdomen are yellow. The males have smaller, 

 more slender antennse, longer pile throughout, and are without the yellow spots and 

 vittulae of the mesonotum, or have only yellowish indications of them. The abdo- 

 men is frequently more brown than black. 



ERISTALIS. 



Eristalis, Latreille, Hist. Nat. Crust. et Ins. xiv. p. 363 (1805). 

 Eristalomya, Rondani, Dipt. Ital. Prodr. ii. p. 40 (1857). 

 Eristalinus, Eondani, loc. cit. 



Synopsis oftlie recognized Central-American species. 



1. Mesonotum with one or more ashy or shining transverse 



bands; arista bare . 11. 



