ART. 11. FLIES OF THE FAMILY CLUSIIDAE MELANDER AND ARGO. 49 



ring, all tibiae slightly dusky due to the covering of stouter hairs; 

 all femora with double row of short flexor setae, becoming stronger 

 on apical half, tibial spurs black and not long. Wings hyaline, \yith 

 an abrupt blackish clouding confined to the apical fourth, a variable 

 pale spot in the cloud in middle of submarginal cell, a distinct cloud- 

 ing over posterior crossvein; sections of costa 4 : 1.5 : 1, of fourth 

 vein 1.5 : 1 : 2.5, of fifth vein 2.3 : 1; halteres white. Length 5 mm. 

 Types. — Six specimens, La Suiza de Turrialba, Costa Rica (Pablo 

 Schild), Melander collection, one deposited in National Museum, 

 Cat. No. 26278, U. S. N. M. The National Museum has a specimen 

 from Corazal, Canal Zone, Panama, secured by August Busck. 



80. SOBAROCEPHALA XANTHOMELANA, new species. 



(Fig. 27.) 



Front and occiput dark ochraccous, ocellar dot black, face and 

 mouthparts yellow, cheeks silvery, facial margin shining yellow^ 

 antennae luteous, the third joint orbicular and with an apical blackish 

 spot, arista short-phunose, black, three times antennal length; lateral 

 bristles of head long, strong and black, five delicate buccal hairs. 

 Mesonotum and scutellum black, a large yellow cordate central spot 

 in front part of notum, metanotum blackish, the metapleurae black, 

 pleurae otherwise pale yellow, no prescutellars. Abdomen black 

 except whitish ovipositor or sometimes ferruginous h3^popygium, 

 valves oval and yelloAvish. Legs with all femora and coxae pale 

 yellow, all tibiae and front tarsi blackish, apical and preapical bristles 

 of middle tibiae strong, four strong setae on underside of front femora 

 in posterior row toward knee. Wings narrow, uniformly infumated, 

 costal ratio 5 : 1 : 1, fourth vein 1:1: 2.8, fifth vein 2:1; halteres 

 whitish. Length 3 mm. 



Types. — Four males and two females, Turrialba, Costa Rica, 

 April to August, Pablo Schild, in Melander collection, and one male 

 from same collector, in National Museum, Cat. No. 26279, U.S.N.M. 

 The aberrent female with yellow dorsal triangle mentioned by 

 Williston in his description of Heteroneura xanthops is very suggestive 

 of the present species. 



BIBLIOGRAPHY. 



Indispensible to the student of this family because of its wealth 

 of detailed information is the Revision der Heteroneuriden by P. 

 Leander Czerny, published in Wiener entomologische Zeitung, volume 

 22, Heft 3, pages 61-107 (1903). The papers that have appeared 

 subsequent to this and to Aldrich's Catalogue of North American 

 Diptera are as follows: 



