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MAR1 41922 
PREFACE. 
NHE Acrydide constitute a group of the short-horned grasshoppers 
which is considered by many authors to bea sub-family of the 
Acridide, from which, however, the Acrydide are distinguished by (1) the 
fact that the claws of the tarsi are not provided with an arolium (or pad 
between the two terminal claws ; also known as a pulvillus) and (2) the 
prolongation of the pronotum backwards over the abdomen. ‘The first 
of the two distinctions is constant and serves to mark the Acrydide 
sharply from the Acridide, but the backward projection of the prono- 
tum is found in some Acridids also. Walker (Ann. Ent. Soc. America 
XII 285; Dec. 1919) finds grounds for considering that the Acrydide 
are more primitive than the Acridide. On the whole, therefore, it seems 
preferable to rank the Acrydids as a distinct family. 
The names under which these small grasshoppers are best known 
to entomologists have usually been variants of the names Tettix and 
Tetriz, both of which are synonyms of Acrydiwm, and, as Acrydiwm 
is the earliest described genus in this group, the family name is derivable 
from that of this genus. 
The Acrydide are small to moderately small insects, usually most 
abundant in damp grassy localities. Many species of the subfamily 
Scelimenine are sub-aquatic, never found far from water and usually 
occurring on wet rocks alongside streams and pools, diving into and 
swimming beneath the water when disturbed, the hind tibie in many 
species being expanded and flattened to form swimming legs. 
Little is on record regarding the life-histories and habits of these 
insects. The immature stages are often found in company with the 
adults on damp rocks, etc., where both appear to feed on moss and other 
low forms of vegetable life. One species has been found as a minor pest 
of cabbages at Pusa. 
The literature on this group is fairly Se the more important 
publications on the Indian forms being :— 
1834. Westwood,. Zoological Journal, Vol. V. 
1839. Serville, Hist. Nat. des Insectes, Orthoptéres. 
1842. de Haan, in Temminck’s Verhandel., Orthoptera. 
1861. de Saussure, “‘ Etude sur quelques Cisshon teres du musée a 
~ Genéve ” (Ann. Soc. Ent. France (4) I 469-494 ; 1860). 
1871. Walker, Cat. of Dermaptera Saltatoria, Part V. 
