FIELD BOOK OF INSECTS. 



Antennae with 21 or 22 joints Tettigidea. 



Antennae with 12 to 14 joints 2. 



Pronotum with a high, arched, median longitudinal 



Nomotettix. 



Top of pronotum rather flat, median ridge low 3. 



3. Vertex of head not projecting beyond the eyes. 



Paratettix. 

 Vertex of head projecting in front beyond the eyes. ... 4. 



4. Pronotum reaching to the eyes Neotettix. 



Pronotum not reaching the eyes Acrydium. 



It is difficult to distinguish, in all cases, 



Truxalinae w t | 1 cer t a inty between this and the next 



or Acridinae ... , 



subfamily. The Truxalmag have no spine 



on the prosternum (or at most an oblique tubercle) and 

 they typically have receding chins. Plate XVIII shows 

 a rather extreme type, Truxalis brevicornis; the antennae 

 are flat at the base and pointed at the apex; side ridges of 

 pronotum straight; general color either green or brown. 

 This species inhabits moist places. Pseudopomala also 

 has flattened antennae and a very oblique face but its 

 prosternum has an obtuse tubercle. In Eritettix the an- 

 tennal joints just before the end are thicker than the 

 others and the apical spur on the inner side of the hind 

 tibiae is twice as long as the other spur. In Mermiria the 

 space between the mesosternal lobes is almost linear in its 

 narrowest part and the metasternal lobes touch. Some 

 other genera (in which, as in these, the head is shorter 

 than the pronotum and not distinctly elevated above it, 

 may be separated as follows : 



1 . No small depressions ( ' ' f oveolae ") on the upper surface 

 of the head between and in front of the eyes or, if present, 

 invisible from above; face very oblique 2. 



Such f oveolae present and visible from above; face less 

 oblique 5- 



2. Hind tibia with 18 to 21 spines on the outer margin. 

 Syrbula. S. admirabilis: male, about i in. long; ground 

 color usually brown; yellow on face, base of antenna, an 

 oblique line from each eye, lower sides of pronotum and 

 parts of hind femora. The female is about 1.5 in. long; 



68 



