372 SUPPLEMENT. 



bristles serially arranged, two rows on the inner and one on the outer edges ; front and middle tarsi 

 slender, tarsal joints gradually decreasing in length, fourth and fifth joints subequal ; hind metatarsi 

 strongly compressed, equal to the three following joints together. Wings large, almost hyaline, veins 

 brown, no stigmal spot, discal cell complete, fourth vein well-developed. 

 Length 3-5 millim., length of wing 4 millim. 



Rah. Mexico, Sierra de las Aguas Escondidas in Guerrero 9500 feet (H. H. Smith). 

 A single specimen. 



Subfam. IIYBOTIN^E. 



HYBOS. 



Hybos, Meigen, in Illiger's Mag. ii. p. 269 (1803). 



Euhybus, Coquillett, Proc. U.S. Nat. Mus. xviii. p. 437 (1896). 



1. Wings rounded, costa with strong spines spinicosta, sp. n. 



Costa straight, without spines 2. 



2. Wings, at least in part, hyaline. Femora more slender ... 3. 



3. Legs wholly yellow dimidiatus, Bell.* 



Legs in part dark brown to black 4. 



4. Halteres yellow. Tarsi black typicus, sp. n. 



Halteres infuscated. Tarsi yellow in part 5. 



5. Stigmal spot well-developed 6. 



Stigmal spot obsolete {triplex, Walk.) 8. 



6. Wings completely hyaline. Tibiae black mellipes, sp. n. 



Wings fuliginous on basal half 7. 



7. Body submetallic triplex, var. loewi (Loew, 



Wien. ent. Monatscbr. v. p. 36). 

 Body shining black triplex, var. tabascensis, n. 



8. Discal cell, at least in basal part, smoky 9. 



Discal cell wholly hyaline 12. 



9. Abdomen purplish triplex, var. purpureus,Wa\k. 



Abdomen shining black 10. 



10. Posterior tibiae and femora black triplex, var. triplex, Walk. 



Knees lighter u 



11. Wings dark on basal half and greyish on rest triplex, var. subjectus, Walk. 



Wings brown on basal half, paler at tip and posterior margin . triplex, var. duplex, Walk. 



12. Pile of mesonotum anteriorly greyish triplex, var. smithi, n. 



Pile brownish to black 13. 



13. Posterior tibiae and femora black. Smaller species .... triplex, var. yucatanus, n. 

 Posterior tibiae and femora brown. More robust species . . triplex, var. bakeri, n. 



* Enumerated, but not identified, by Osten Sacken in the earlier part of this work. 



