2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 121 



mouthparts darkened. Mesonotum subshining, dark reddish brown 

 medially, somewhat paler laterally; pronotum yellowish brown but 

 not contrasting mth sides of mesonotum; hairs and setae of meso- 

 notum brown; scutellum yello^\^sh brown with four setae; pleuron, 

 postnotum, and halter yellow brown. Wing hyaline, slightly tinged 

 with yellow; veins dark; subcosta ending just before level of radial 

 sector fork; under side of subcosta with row of long hairs. Foreleg 

 yeUow bro^vn, the tarsus shghtly darkened; midleg the same but tibia 

 darkened except at extreme base; hindleg mostly yellowish, the coxa 

 posteriorly and femur near apex darkened. Dorsum of abdomen 

 nearly black except for tergum I, tergum II laterally, tergum VIII, 

 and terminalia, which are brownish yellow; venter yellowish with 

 some darkening laterally before apex. Length 2.5-3.5 mm. Wing 

 3-4 nma. 



Male: Coloration as in female. Eyes nearly touching. Genital 

 capside not as long as terga VI and VII combined whereas this is 

 longer in M. divergens. Slightly smaller than female. 



Distribution: Dominica, Lesser Antilles; probably Co^ta Rica. 



Holotype: 9, Clarke Hall, Jan. 18, 1965 (Wirth). 



Paratypes: Clarke Hall, Mar. 21-31, 1965, 1 9; Clarke Hall, Feb. 

 11-20, 1965, 1 9 (all Wirth). (USNM nos. 68, 116.) 



A single specimen bearing the data "La Suiza de Turrialba, Costa 

 Rica, Aug. Pablo Schild" in the U.S. National Museum is apparently 

 this species. It differs only in having the midtibia paler. 



Because of the contrasting yello\\dsh tip of the abdomen, I use as 

 a specific name the generic name of the flounder knoAvn as the YeUow 

 TaU. 



The three New World species of Mycetobia may be differentiated 

 by the following key: 



1. Subcosta bare (Nearctic) divergens Walker 



Subcosta with numerous long setae ventrally (Neotropical) 2 



2. Thorax, abdomen, and legs strongly patterned with dark markings; wing 



more than 5 mm long stonei Lane and Andretta 



No distinctive pattern except for yellowish at base and tip of abdomen; 

 wing not more than 4 mm long limanda, new species 



Olbiogaster danista, new species 



Female: Frons and occiput dark, grayish pruinose, only the ocellar 

 triangle shining black; scape and pedicel yellow, flageUum black; face 

 yellow, in some slightly darkened above; palpus and mouthparts 

 yellow. Thorax mostly yeUow wdth yellowish and some brown hairs, 

 with or A\dthout a pair of elongate darker markings on mesonotum 

 anteriorly, and a darkened spot on upper mesopleuron; scutellum 

 dark except at base, with a row of many dark hairs; postnotum some- 

 what infuscated medially; halter with yeUow stem, black knob. 



