OCYPTAMUS. — BACCHA . 



31 



feet, Venta de Zopilote 2000 feet, all in Guerrero (H. H. Smith), Teraax in North 

 Yucatan (Gaumer). —Soutr America, Colombia 2 , Brazil 1 3 . 



Ten specimens, all females. It is not at all improbable that the hitherto unknown 

 male will be found to be identical with those described on p. 17 as Syrphus, no. 8. 



The following species have been described by Bigot : — 



Ocyptamus infuscatus, Bigot, Ann. Soc. Ent. Fr. 1883, p. 324. — Mexico. 



fraternus, Bigot, loc. cit. p. 324. — Mexico. 



fenestratus, Bigot, loc. cit. 1885, p. 251. — Mexico. 



BACCHA. 

 Baccha, Fabricius, Syst. Antl. p. 199 (1805). 



Synopsis of the recognized Central-American species. 



1. Alulaj small or rudimentary ; slender species (except luctuosa) 2. 

 Alulae of the usual size 8. 



2. Face in profile strongly projecting, forming nearly a straight 



edge with the front to the oral margin nasuta, sp. n. 



Profile of face receding 3. 



3. Face in profile nearly straight and receding from the antennse 



to the oral margin ; not at all tuberculate 4. 



Face with a well-developed tubercle 5. 



4. Thorax metallic black ; small species gracilis, sp. n. 



Thorax in great part red rubida, sp. n. 



5. Wings much shorter thanthe abdomen, hyaline, with a brown 



stigma ; front of f emale with fine transverse wrinkles ; 



abdomen very slender stenogaster, Willist. 



Front of female without transverse wrinkles 6. 



6. Anai angle acuminate, with a concave basal border; pleurse 



and pectus yellow attenuata, sp. n. 



Basal border of anal angle convex ; pectus, at least, metallic 

 blue-black 7. 



7. Wings yellowish, with the anterior border indefinitely brown 



or brownish punctifrons, sp. n. 



Wings uniformly deep yellowish-brown ; ocelli remote from 



vertex luctuosa, Bigot ? 



Wings hyaline, with the anterior border definitely dark 



brown laudabilis, sp. n. 



