1889.1 411 



towards the base ; the scapular (scap ar) between the mediastinal and anterior 

 radial veins ; the anterior radial (a r ar) between the anterior and middle radial 

 veins, this is the " area externomedia " of Fischer and Brunner ; the posterior radial 

 (pr a r) between the posterior and middle radial veins (area sub-externomedia, 

 Fischer) ; the discoidal (disc ar) between the posterior radial and anterior ulnar 

 veins ; the ulnar (u ar) between the two ulnar veins (area interulnaris, Brunner) ; 

 and the anal (an ar). I have ventured to give the names anterior radial, posterior 

 radial, and ulnar to these areas, because it seems advantageous that the areas should 

 be named in relation to the veins ; L. Fischer had them so, but his names were very 

 cumbersome, and while Brunner and the more modern writers have adopted the 

 terms radial and ulnar as applied to the veins, they still retain Fischer's names for 

 some of the areas, and it seems to me that the names which I suggest are wanted to 

 complete the system. 



The stridulation in the Acridiidce is produced by the rubbing together of the 

 posterior femora and tibiae and the side of the folded elytron. The sound varies in 

 intensity in different species, and some of the common grasshoppers (Stenobothrm) 

 may be thus distinguished even when not in sight. In St. bicolor and St. parallelus 

 the sound seems to be produced both at the upward and downward stroke of the 

 limb ; but in the former it is harsher, louder and longer, while in St. viridulus the 

 sound is only produced, or at any rate only heard, at the downward stroke. These 

 differences though slight soon become familiar to the ear, and are very useful when 

 collecting. When stridulating the insect carries the tibia folded up close to the 

 lower border of the femur. 



August and September are the best months for collecting ; before 

 the middle of August many of the insects are immature. 



Table of Genera. 



1 (10) Tarsi with a pad between the claw3 ; pronotum never produced beyond 



the metanotum. 



2 (9) Prosternum plain. 



3 (8) Mediastinal and scapular areas of the elytra with the transverse veins 



parallel. 



4 (5) Foveolse of the vertex almost absent, or forming a small triangular de- 



pression behind i. Mecostethus. 



5 (4) Foveolse of the vertex well marked, oblong. 



6 (7) Antennae filiform ii. Stenobothrus. 



7 (6) Antenna? clubbed at the apex iii. Gomphoeerus. 



8 (3) Mediastinal and scapular areas of the elytra irregularly veined... 



iv. Pachytylus. 



9 (2) Prosternum with a central cone-shaped protuberance . v. Schistocerca. 

 10 (1) Tarsi without a pad between the claws ; pronotum produced backwards 



into a long process vi. Tettix. 



i.— MECOSTETHUS, Fieber. 

 Only the basal part of the foveolse of the vertex is seen in Me- 

 costethus, and these form small triangular depressions with their bases 

 towards the eyes. They are fairly well marked in some specimens, 

 but almosb obsolete in others. 



