444 



FAMILY XT. STAPH 



ing processes or lacinias of varying shape, frequently long and slen- 

 der and decurved, resembling somewhat the forceps of an earwig, 

 often broader in the form of triangular plates. The sixth segment 

 varies also in form and sculpture, the hind margin being notched in 

 most species and the surface concave or impressed, the impression 

 often wholly or partly filled with very short, stout bristles, thus 

 forming a " spongy space." The hind margin of the sixth ventral 

 in part of the species is also pectinate or fringed on each side with 

 stiff, close-set spinules, thus forming a comb-like structure. 



In the female the front tarsi are not dilated and the last ventral 

 is (a) either entire and fringed behind with short equal spinules 

 (flavipennis and circumcinchis only) or (&) divided into six rather 

 long and slender processes. In the latter case the last dorsal is tri- 

 iobed, with the middle lobe either entire, emarginate, bifid or trifid 

 at apex. In the key the characters given pertain only to the male, 

 unless the female be mentioned specifically. 



KEY TO INDIANA SPECIES OF TACHINUS. 



a. Sixth ventral pectinate on its hind margin. 



1). Sixth ventral with a spongy space on the center of the impression; 

 female with middle lobe of last dorsal shorter than the side lobes, 

 slender and feebly notched at tip. 849. memnonius. 



J)b. Sixth ventral without a spongy space at middle, very deeply emargi- 

 nate, the angles prolonged. 

 c. Spinules on hind margin of sixth ventral bordering the entire 

 emargination ; female with middle lobe of last dorsal as long as 

 the side lobes, deeply divided to form two slender processes ; pic- 

 eous, the sides and base of thorax paler. 850. repandus. 



cg. Spinules divided into three groups; pale reddish-yellow; length 

 3.5 mm. scrutator. 

 aa. Sixth ventral segment not pectinate on hind margin. 



d. Form parallel; abdomen not narrowed except at tip; female as in 

 repandus. parallelus. 

 dd. Abdomen gradually narrowed from base to tip. 

 e. Sixth ventral with a spongy space on its middle. 



/'. Abdomen rather coarsely punctured; elytra clay-yellow; female 

 with last ventral entire, last dorsal with the three lobes united. 



851. flavipennis. 



/'/'. Abdomen very obsoletely punctured ; female with middle lobe of 

 last dorsal as long as and broader than the side lobes, the tip 

 notched one-third toward base. 852. luridus. 



ee. Sixth ventral without a spongy space on its middle. 

 g. First two ventrals strongly carinate at middle. 



h. Processes of last ventral long and curved; last dorsal with 

 four acute teeth; elytra pale brown, their tips piceous; fe- 

 male with middle lobe broad, shorter than side ones, and 

 triangularly notched at tip. 853. fimbriatus. 



