68 ACADEMY OP NATURAL SCIENCES 



LEPTOGASTER Meig. 



L. ANNULATUS. — Feet whitish, annulate with rufous. 



Inhabits Pennsylvania. 



Antennae and trophi whitish ; thorax pale cinereous, with three 

 dilated pale brown lines ; wings hyaline, immaculate ; anterior 

 and intermediate feet white, extremities of the joints tinged with 

 rufous or yellow, posterior feet more robust and elongated, joints 

 yellow, white at base, thighs clavate, bifasciate with rufous near 

 the tip, tibia trifasciate with [76] rufous; abdomen cylindric, 

 elongated, dilated at tip, segments yellow-brown, dark reddish- 

 brown at base and on the terminal submargin, terminal margins 

 white. 



Length two-fifths of an inch nearly. 



The nervures of the wings of this insect, do not perfectly cor- 

 respond with those of L. ti^ndoides, which circumstance, com- 

 bined with another highly important diflference that this insect 

 exhibits, in having but two nails to. the tarsi, would justify the 

 generic separation of the anmdahis from the tipidoides, and its 

 reference to a distinct genus. 



It is not a Phtliiria of Wiedemann ? 



[Name changed to L. histrio, by Wiedemann. — Sacken.] 



HYBOS Meig. 



H. THORACicus. — Thorax ferruginous, trilineate ; abdomen 

 piceous. 



Inhabits Pennsylvania. 



Antennae and rostrum yellow, pale ; thorax ferruginous, with 

 three dilated black lines : wings obscure, a dark red-brown stig- 

 ma; feet reddish-brown, the posterior pair darker than the 

 others, tarsi yellowish ; abdomen dull-piceous. 



Length rather more than one-fifth of an inch. 



BIBIO Latr. Meig. 

 1. B. PALLIPES. — Black; tergum with a yellowish-piceous 

 lateral margin. 



Inhabits Pennsylvania. 



Body hairy ; wings hyaline, a large fuscous stigma, [77] inter- 

 :Jtice of the first and second nervures yellowish ; feet whitish- 



[A^ol. III. 



