FAM. LOCUSTID.E 3 



of foramina are as follows : The open foramina, tympanum apertum of Brunner, is an open cavitv opening 

 laterally in the side of the tibiae, the covering membrane usually plainly exposed to view (Plate, Fig. 8 ). 

 The shell-shaped or ear-like foramina, tympanum conchatum of Brunner. has the hind margin of the 

 strengthened frame of the orifice drawn over the opening like an ear or a shell, covering but not closing 

 the foraminum (Plate, Fig. 9). The linear foramina, tympanum rimalum of Brunner, is similar to the 

 last, but here the covering shell closes the orifice completely, leaving only a fine slit visible (Plate, 

 Fig. I 0). The last two forms, especially the second, open more or less anterior!}' as opposed to the first 

 described form, which open laterally. The foramina of the opposite sides of the tibiae are usually of the 

 same form, but occasionnallv that of one side is of one form, while that of the opposite side is of another. 



The organs of flight are much used in generic and specific determination. Their absence or 

 presence and, when present, their development and shape are important characters, and the venation, 

 especially of the elytra, is often used in classification. The main veins of the elytra and wing are 

 named in Figures 11,12 and 13. The males of most winged Locustida? are very musical and the 

 elvtra are furnished with specialized stridulating areas. These sound producing organs are called crepi- 

 taculii, taboretts or tympanii, the last preferable as it is the most used. The}- are best developed on 

 the right elytron and in both elytra they are usually limited to the anal field. 



The classification of the Locustidae. while fairly satisfactory as compared with some other groups 

 of insects, is not perfect by any means. Many of the subfamilies have been monographed more or less 

 elaborately and with varying success. The gioup relationship of man} - of the forms is but poorly indi- 

 cated by many of the published tables, the writers seemingly preparing a theoretic table and then 

 forcing various forms in where their natural characters illy justify their being placed. It is an almost 

 impossible task, however, to construct keys to higher groups which will unfailingly carry all species into 

 their proper places, owing to the almost infinite variation of nearly all taxonomic characters. With 

 sufficient material much improvement could certainly be made on the classification which follows. The 

 tables are mostly compilations of ones previously published, not enough material of the world's richness 

 of form being available to justify an}" material revision. 



The subfamilies of the Locustida; may be separated by the following key, which is mostly an 

 adaptation from the works of Brunner : 



KEY TO THE SUBFAMILIES OF LOCUSTID.E 



i. Tarsi tliree-jointed 22. 



— Tarsi four-jointed. (In the American genus Daihinia of the subfamily 



Rh.idophnrinae the fore and hind tarsi are tetramerous and in at least 



some species of a related genus the fore tarsi are three-jointed.) 2. 



2 . Tarsi more or less depressed 3 . 



— Tarsi distinctly compressed. (Usually apterous.) 21. 



3. Anterior tibiae provided with foramina 4. 



— Anterior tibiae without foramina 20. 



4. Antennae inserted between the eyes, less remote from the top of the occiput 



than from the clypeal suture (Plate, Fig. I) 5. 



— Antennae inserted below the eyes or between their lower margins, nearer the 



clypeal suture than to the top of the occiput (Plate, Fig 2) 1S. 



5. First and second tarsal joints smooth (Plate, Fig. 6.) (Hind tibiae with 



an apical spine above on each side.) Subfam. Phaneropterin.*:. 



— First and second tarsal jointslongitudinally sulfate laterally (Plate, Fig. 7) 6. 



