46 



SUB-FAMILY PYRGOMORPHINAE. 



The insects belonging to this sub-family are somewhat 

 aberrant when we take into consideration the forms which 

 occur in this country, the typical forms of the group having 

 the face very much slanting towards the rear and the apex 

 of the head considerably advanced in front of the eyes, 

 while the Argentina forms have the face nearly perpendicular 

 and the vertex little or not at all advanced in front of the 

 eyes. The typical form of the body of these insects also is 

 somewhat slender, smooth, and fusiform, while here in Ar- 

 gentina they are very obese and more or less covered with 

 spines and wart-like projections. Some of the species are 

 quite numerous in jDortions of the country and have been 

 even reported at different times to attack and destroy the 

 tobacco plant which they feed upon. 



TABLE FOR SEPARATING THE GENERA. 



A. Body more or less graceful and cylindrical, somewhat mgose. The 



anteuniv filiform. Pronotiuu feebly carinated. 



b. Tegmina and wings perfectly developed, extending considerably 



beyond the tip of the abdomen in both sexes. Carina' of hind 



femora smooth. Internal angles of mesosternal lobes rounded at 



apex. OSSA Giglio-Tos. 



bb. Tegmina and wings somewhat abbreviated. Carin;eof hind femora 



toothed. Internal angles of mesosternal lobes not rounded. 



OMMKXECHA Serville. 

 A A. Body very obese and greatly depressed: coarsely tuberculate. cari- 

 nated and spined. Antenna' with the joints somewhat flattened, 

 subensiform. Pronotal carina always more or less cristate, 

 bb. Tegmina and wings present. Pronotum without the lateral 

 toothed, leaf-like expansion; its hintl Itoi'der broadly angulate 

 and adorned with five flat, tooth-like projections— the middle one 

 furcate. SPATHALITM Bolivar, 



b. Tegmina and wings wanting. Pronotum furnished at lower late- 

 ral edges with a toothed, leaf-like expansion: its hind border 

 broadly rounded and adorned with a series of six distinct, heavy, 

 blunt spines. GKyKA Philippi. 



Fig. 15. — Ossa vh'idis. and tip of vertex. 



