234 PROCEEDINGS OP THE ACADEMY OP 



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L. macrocera. Nigra, nitida ; femoribus flavo ferrugineis, apice fusco ; 

 alis fusco-maculatis ; long. lin. 3-4. 



Limnobia macrocera Say, Jour. Acad. Phil. iii. p. 20, 2. 



Antennae black, except the basal joints, which are tawny ; proboscis and 

 palpi black ; front above the antennae and lower part of the head yellowish- 

 ferruginous ; vertex black, shining. Thorax black, shining ; pleurae slightly 

 hoary ; halteres pale yellow, (the 9 specimen have a brown knob) ; feet dark 

 tawny ; coxae and base of femora paler ; tips of femora, tibiae and tarsi brown. 

 Abdomen black ; three or four intermediate segments with pale ferruginous 

 spots at the base (more distinct in living specimens) ; genitals ferruginous- 

 yellow. Wings hyaline, spotted with brown ; one spot near the base, in the 

 angle between the subcostal and pobrachial veins ; another square one, near 

 the origin of the petiole, between the same veins ; a third one between the 

 costa and the cliscal areolet ; the tip of the wing, as well as the discal cross- 

 veins, are clouded. In some specimens (for instance in my tf from Florida,) 

 a nebulosity extends along the pobrachial, anal and axillary veins ; it occu- 

 pies the whole extent of the arese between these veins ; the nebulosity at the 

 tip of the wing has, in such cases, also a greater extension. The neuration is 

 like Meig. i. tab. vi. f. 3, only the second radial and cubital areae are nearly of 

 the same length, the radial vein forking immediately beyond its origin. 



I found rf specimens quite commonly on the 2d of July, 1859, near the so-call- 

 ed Salt-pond in southern Virginia, (about 20 miles from the Montgomery White 

 Sulphur Springs.) Another tf specimen I caught in Florida, in March, 1858. 

 Of my three 9 specimens I found two near Washington, and received one 

 from Dr. Asa Fitch, of Salem, N. Y. There is a very strong probability that 

 these 9 belong to the same species ; but having never found both sexes in 

 the same locality, I cannot affirm it positively. 



N. B. Say commits a mistake when he compares the neuration to Meig. i. 

 tab. v. f. 7. Wiedemann quotes correctly Meig. i. tab. vi. f. 3. 



2d Section. 

 (Subgenus Idioptera Macquart. ) 



Wings like Meigen i. tab. iv. f. 16, or Schumm. tab. iv. f. 4. Pobrachial 

 areolet divided in two sections by a supplementary cross-vein in its middle. An- 

 tennae of the $ longer than head and thorax together, with elongated subcy- 

 lindrical, densely pubescent joints ; two basal joints short. 



The 9 of the European L. fasciata has rudimental wings and cannot fly. 

 (Figured in Schum. tab. v, f. 2.) 



A (^ specimen from Massachusetts, for which I am indebted to Mr. Scudder, 

 in Boston, corresponds pretty closely to Schummel's description of L. 

 fasciata. 



L. fasciata. Capite thoraceque cinerascentibus, abdomino silaceo, fusco- 

 marginato et fasciato, alis hyalinis, fasciis duabus, maculisque pluribus fus- 

 cis ; length 3 lin. 



Limnobia fasciata (Linn.?) Schummel, Limnob. p. 183. 



Head brownish cinereous : palpi and antennae black. Thorax cinereous, 

 pleurae and metathorax hoary ; scutellum pale ; halteres tawny, with brown 

 knob ; feet brown ; coxae and base of femora pale ochreous. Abdomen och- 

 raceous, lateral and posterior margins of the segments brown ; $ forceps 

 tawny. Wings hyaline, with two bands formed of brown spots ; a spot at 

 the tip and several small dots between it and the second band. 



3 c? Section. 



Neuration of the wing like 2d Section, (Meig. i. tab. iv. f. 16,) a supplementary 

 cross-vein dividing the pobrachial areolet in two sections. Antennae hardly reaching 

 beyond the origin of the wing; joints of the flagellum subglobular. 



[Aug. 



