ORTALIDAE. 39 



genus Tseniaptera Macq., this family approaches so much to the 

 Ortalidae, that the bareness of the first longitudinal vein, the 

 difference in the structure of the female ovipositor, and the corre- 

 sponding difference in the structure of the male appendages, must 

 be considered as the chief characters, which distinguish it from 

 them. The Sepsidse, too, are rather nearly related to the Micro- 

 pezidse, but are distinguished from them not only by the structure 

 of the female ovipositor, but also by their palpi being always rudi- 

 mentary. 



The N. A. species I know of are : one true CALOBATA, nume- 

 rous T.ENIAPTER.JE, and two MiCROPEZuE. Whether the N. A. 

 species which Mr. R. Desvoidy refers to the genus oSTERius, really 

 belong to it, appears to me most doubtful, as they seem to be 

 Tceniapterce all together. The genus LISSA Meig. occurring like- 

 wise in N. A., in most characters agrees with the Micropezidce, and 

 may provisionally be placed among them, till a more convenient 

 place in the system will be pointed out for it. The genus EUME- 

 TOPIA erected by Mr. Macquart on a N. A. species, is also related 

 to the latter, and may likewise obtain here a provisional place. 

 Both these genera differ from the great bulk of the Micropezidce 

 by having the legs less slender, the tarsi less abbreviated, and the 

 last segment of the abdomen not prolonged so as to form a cylin- 

 drical tube. 



FAM. XLIII. ORTALIDAE. 



Charact. Neuration of the wings complete ; auxiliary vein separated from 

 the first longitudinal vein and running to the border of the Ving 

 in the usual way, under an acute angle and remaining perfectly 

 distinct 'in its whole length ; third longitudinal vein generally 

 with coarse hairs ; two posterior basal cells large, and the outward 

 one frequently prolonged in an acute angle. Front with bristles on 

 the upper part only ; no vibrissse at the border of the mouth ; 

 clypeus commonly very much developed, and proboscis often very 

 much thickened. Middle tibiae alone with spurs ; no tibiae with 

 an erect bristle on the exterior side before the tip. Ovipositor of the 

 female rather flattened and horny, consisting of three elongated 

 segments, forming three drawers like those of a telescope, and end- 

 ing in a simple point. 



The family of Ortalidce is exceedingly rich in variously shaped 

 organizations, which caused a considerable increase of genera in 



