NATURAL SCIENCES OP PHILADELPHIA. 251 



U. pi 1 o s a Schum. (?) Walker, Ins. Brit. Dipt. iii. p. 308, tab. xxviii. f. 4. 



Limnobia pilosa Schum. Limnob. p. 150, tab. i. f . 7 ; Zetterstedt, Dipt. 

 Scand. x. p. 3886, 62. . 



Long. lin. 3. 



Front and vertex light cinereous ; proboscis infuscated, palpi and antennae 

 black ; two basal joints of the latter short, yellowish ; the following joints 

 elongated, subcylindrical, verticillated and covered, besides with a short 

 pubescence. Thorax yellowish cinereous, paler on the pleurae, a brownish 

 stripe in the middle of the praescutum ; lateral stripes almost obsolete ; scutum 

 infuscated ; scutellum pale ; halteres pale ; the knob infuscated at the tip ; 

 feet tawny, infuscated at the tips of femora, tibiae and tarsi ; coxae and basis of 

 femora pale. Abdomen brownish, venter paler, 9 ovipositor falciform, short, 

 ferruginous Wings brownish cinereous, finely, densely and uniformly pilose 

 over the whole surface ; veins brown ; this pubescence is not woolly as in 

 Erioptera, and affects but little the transparency of the wing ; stigma ellipti- 

 cal, but little darker in color than the wing itself; a slight brown nebula on the 

 central cross- vein ; no petiolate areolet ; stigmatical cross-vein near the tip 

 of the subcostal vein, and a little beyond the middle of the upper branch 

 of the radial fork. (Compare also the above quoted figures of Westwood 

 and Schummel.) 



A single 9 specimen from Washington (nob.) 



At first glance, this species has a striking resemblance to Limnophila 

 pilosa nob., especially on account of the pubescence of the wings. It is 

 easily distinguished, however, by the position of the mediastinal cross -vein, 

 the structure of the antennae and that of the 2 ovipositor, which is larger in 

 Limnophila pilosa, etc. 



Protoplasa nob. 



Proboscis sfout, ending in a thick labium ; both together are as long, or a little 

 longer than the head. Palpi longer than the head, joints elongated. Antennae 

 15-jointed, shorter than head and proboscis together, setaceous, verticillated ; 

 first joint short, cylindrical ; 2d, stout, subglobular ; the following joints 

 cylindrical, compressed, short ; the five last joints more oval, elongated. Front 

 broad. Thorax gibbose ; suture deeply sinuated; scutellum large, projecting 

 over the metathorax, which is short. Abdemen rather short, stout. Feet 

 moderately long, slender; tibiae armed at the tip with moderately long, 

 strong, divaricated spurs ; pulvilli indistinct ; ungues smooth. Wings broad ; 

 anal angle square ; the narrow portion long and nearly linear ; neuration 

 very like that of the genus Macrochile Loew, (see Linnasa Entomologica, 

 vol. v. tab. ii. fig. 25); the only differences are, 1st, that Protoplasa 

 has a cross-vein between the discal areolet and the next longitudinal vein 

 (towards the posterior margin,) which cross-vein closes a second, smallei' 

 discal areolet. 2d, it has a stump of a vein at the angle, formed by the 

 petiole, near its origin. 



This remarkable genus is closely allied to the fossil genus Macrochile 

 Loew (1. c. p. 402) found in the Prussian amber, but with the following differ- 

 ences : 1st, Macrochile has a much longer proboscis ; 2d, its antennae are 

 19-jointed, and more than twice as long as head and proboscis together ; 3d, 

 the anal angle of its wing (judging from the above mentioned figure) is rounded 

 and not square; 4th, the neuration of the wing is somewhat different, (see above.) 



The relation of Protoplasa with Ptychoptera and Bittacomorpha 

 is evident : the struoture of the mouth, that of the antennae and feet, the deep 

 sinuosity of the thoraoic suture, as well as many analogies in the neuration of 

 the wings, indicate it sufficiently. But Protoplasa seems different from 

 both by the small size of the metathorax. (*) 



(*) I am not able to make this statement positively, as the meso- and metathoracic re- 

 gion of both my specimens was injured by the pin. 



1859.] 



