170 



8 (1) Head vertical, the mouth parts below; hind femora very much 

 stouter or very much longer (or both) than the middle femora. [Sal- 

 tatorial.] 

 9(10) Antenna? much shorter than the body, filiform, clubbed or ensi- 

 form, but if the first, scarcely tapering; the joints distinct, often 

 depressed; ocelli three in number; tarsi 3-jointed, similar in struc- 

 ture on all the legs ; base of the male tegmina with no tympanum 

 on dorsal surface ; ovipositor composed of a double pair of short 



arcuate plates, vertically divergent at tip Acrydii. 



10 (9) Antennae much longer than the body, setaceous, delicately taper- 

 ing ; ovipositor usually prolonged into a compressed blade or needle. 



11 (12) Ocelli generally wanting ; tarsi (at least of middle legs 1 ) 



4-jointed, nearly similar in structure on all the legs (but see 

 note); fore-coxae usually broader than long; middle field of teg- 

 mina, like the costal field, nearly or quite vertical when closed; 

 base of <S tegmina (when present) furnished on doi'sal surface 

 with a tympanum, 2 limited to the anal area, and crossed by a 

 prominent nervure formed by the last axillary vein ; ovipositor 

 (when exserted) forming a strongly compressed, generally ensi- 

 form blade, the inner valves almost always partially exposed the 

 entire length of the ovipositor, the tip not expanded. Locustariae. 



12 (11) Ocelli sometimes present, sometimes absent ; tarsi 3-jointed, 3 ' 



those of either the fore legs, or else of the hind legs, differing 

 from the others in structure; fore coxa? longer than broad; mid- 

 dle field of tegmina, like the anal field, nearly or quite horizontal 

 when closed 4 ; base of <3 tegmina (when present) furnished on 

 the dorsal surface with a tympanum extending across the anal 

 and median areas, crossed by a prominent nervure formed by the 

 anal vein; ovipositor (when exserted) forming a nearly cylindrical, 

 straight or occasionally upcurved needle, the inner valves gen- 

 erally scarcely exposed, except at the expanded tip . Gnyllides. 



For general descriptive and methodical orthopterological works, treating 

 amon»- others of N. American insects, the student may consult Burmeister's 

 Handbuch der Entomologie, Vol. n, part ii, Gymnognatha, 8vo, 1838 

 (descriptions mostly in Latin); Serville's Orthopteres, 8vo, 1839 (French); 

 Saussure's Melanges Orthopterologiques, fasc. i-iv. 4to, 1863-72, including 



i In Daihinia the fore and hind tarsi are 3-jointed. 



2 There are exceptions to this in exotic genera. 



3 Stal is inclined to place in the Gryllides the Stenopelmati and Gryllaorididae, which 

 have 4-jointed tarsi, but coxaj longer than broad; I have, however, left them, as has 

 usually been done, in the Locustariae. 



4 The Asiatic Schizodactylus is a curious example of a Locustarian, with an enor- 

 mously developed anal (horizontal) field, giving it the aspect of a Gryllidan. Many 

 Orthopterists consider it as such. 



