150 KANSAS UNIVERSITY SCIENCE BULLETIN. 



rounded posteriorly; marginal cell obtuse at apex, the appendiculation 

 rather indistinct ; legs -stout, spinose ; abdomen often depressed ; pygidial 

 area always with appressed pile or bristles, which are usually metallic in 

 color. 



J' . Comb of fore tarsi composed of stout thorns; pygidial area well 

 defined by carinate borders. 



2 ■ Fore femora simple or emarginate beneath; fore coxse with or 

 without an elongate process; pygidium with or without carinate borders; 

 its pubescence, in all the species which I have seen, is silvery; eighth 

 ventral segment emarginate. 



This genus, which Fox divides into two sections, is well represented in 

 our state. These are perhaps the most commonly seen of our larrids. 



Key to the Species of Tachytes. 

 Females. 



1. Anterior margin of clypeus produced in the middle into a rather 



narroiv lobe (figs. 52 and 56) ; lateral margins of clypeus dis- 

 tinctly dentate; legs (femora and tibije) largely ferruginous. . 2 

 Anterior margin of clypeus not produced into a lobe, though most 

 frequently rounded out, .sometimes slightly emarginate mesad 

 and usually dentate laterally; legs (except in the large, yel- 

 lowish-winged species distinctus) black 3 



2. Pygidium scarce constricted preapically, covered with fine golden 



pile validiis 



Pygidium somewhat constricted before apex (fig. 90), its bristles 

 bronzy mandibiilaris 



3. Clypeus armed with a large prong on either side (fig. 61) ; py- 



gidium triangular (fig. 93), with rather sparse, stout, appressed 



bristles, which are pale golden or silvery 7nergus 



Clypeus without a lateral prong; pygidium well covered with pile 

 or fine bristles (figs. 91 and 92) 4 



4. Clypeus rounded out, armed laterally with more or less distinct 



teeth ; abdomen black or black and ferruginous 5 



Clypeus without teeth (fig. 54), its anterior margin subtruncate, 

 with a slight production mesad; abdomen black with brassy or 

 silvery fascise; wings light fuscous obductits 



5. Metatibije with at least the basal half of the outer posterior row of 



spines short, blunt and thorn-like, the row much stouter than 

 those on the first joint of the hind tai'si, and usually extending 

 to quite near the base of the tibiae (fig. 82) ; pygidium (at least 

 in fresh specimens) with some erect hair in addition to the fine 



appressed pile; species rather small 6 



Metatibiffi with the spines not short as in the above, usually well 

 pointed and differing but little from those of the first joint of 

 the hind tarsi, and usually ending (or beginning) at a good 

 distance before the base of the tibise; no erect hair on pygidium, 

 the latter golden or bronzy 7 



