502 Mr. F. W. Edwards o7i Three new Species 0/ 



LXT. — Three new Species of the Dipterous Genus Olbio- 

 gastcv, O.'S., in the British Museum Collection. By 

 F. AV. Edwards, B.A., F.E.S. 



(Published by permission of the Trustees of the British Museum.) 



The genus Olhiogaster was founded by Osten-Sacken in 1886 

 (Biologia (Jentrali- Americana, Di[)tera, vol. i. p. 20) for an 

 insect belonging to the family Rhyphida;, of wjiicli he had 

 seen specimens from Costa liica and Porto Rico; at the 

 same time he referred to the new genus Bellardi's Rhyphus 

 i(nuiatus, described from Mexico. Townsend (Ann. & Mag. 

 Nat. Hist. ser. 6, xx. p. 21, 1897) recorded another specimen 

 o£ 0. tceniatus from Mexico ; AVillistnn in 1901 (Biologia 

 Centr.-Amer., Dipt. vol. i. SuppL p. 229, and pi. iv. fig. 6) 

 described and figured another Mexican specimen ; and, finally, 

 Enderlein in 1910 (Stett. eiit. Zeit. vol. Ixxi. p. Qb) described 

 another species from !Soutli Brazil. 



It will thus be seen that the very few known specimens of 

 this interesting genus were all obtained in the Neotropical 

 region. The British ]\luseum contains examples of two 

 additional species from AWst Africa and Ceylon, and, as these 

 specimens so greatly extend our knowledge of the geo- 

 grajthical range of the genus, it seems worth while to describe 

 them. At the same time it may be desirable to give a name 

 to the specimen figured by Williston and to call attention to 

 some inaccuracies in his depiction of the wing-venation. 



1. Olhiogaster sackeni, sp. n. (Williston MS.) 



Til is name is proposed for the above-mentioned specimen 

 figured by Williston, who refrained from naming it iiimself 

 as he was unable to compare it with the description of 

 0. ta'niatusy Bellardi. According to this latter description 

 there is a very marked difference in the coloration of the legs 

 in the two specimens, and, while it is indeed possible tiiat 

 they represent merely varieties of one species, it will, in view 

 of this difference, be convenient to refer to Williston's 

 specimen under a separate name. The distinction is as 

 follows : — 



O. tceniatus^ Bell. Legs black, the apex (^parte antica) of 

 the front femora, the front tibite, the base of the middle and 

 hind tibise, and the apex of the iiind femora yellow. 



0. sacktni, sp. n. Legs yellow, the base of the four 

 anterior femora, the whole of the hind femora, the extreme 



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