32 8 ORTHOPTERA CHAP. 



The geological record is rather obscure in ^ the matter of 

 Locustidae. Scudder considers that a fair number of Tertiary 

 forms are known, and says that they represent several of the 

 existing tribes and genera. One or two have been found in 

 j\Iesozoic rocks. 



Table of the Tribes of LocnsiiDAE 



1. Tarsi more or less depressed. 



2. Front tibiae furnished with auditory cavities. 



3. Antennae less distant from the summit of the occiput than from 

 the labrum ; inserted between the eye.s.i 



4. First two joints of the tarsi laterally smooth. (Posterior tibiae 

 furnished on each side with an apical spine.) Tribe 1. 

 Phaneropterides. (Fig. 196, Microcentrum ; Fig. 199, 

 Myrmecophana. Fig. 101, Poedlinion affinis.) 

 ' 4'. First two joints of the tarsi laterally, longitudinally sulcate. 



5. Foramina of the anterior tibiae normally open. (Fig. 

 193, A.) 



6. Posterior tibiae furnished on each side with apical spines. 

 7. Prosternum unarmed. Tribe 2. Meconemides. 

 T'. Prosternum bispinose or bituberculate. Tribe 3. 

 Mecopodides. 

 6'. Posterior tibiae with no apical spines. (Head prognath- 

 ous.) Tribe 4. Prochilides. (Fig. 200, Phasmodes.) 

 5'. Foramina of the anterior tibiae forming a chink, or pro- 

 tected by a scale. (Fig. 193, B.) 

 6. Anterior tibiae with no apical spines. 



7. Margins of the scrobes- of the antennae prominent. 

 Tribe 5. Psbudophyllides. (Fig. 187, Gyrtophyllus 

 crepitans ; Fig. 198, Pterochroza ocellata.) 

 7 ' ^Margins of the scrobes of the antennae not prominent. 

 8. Posterior tibiae furnished above on each side with 

 apical spines, or with a single spine on the side. 

 9. Posterior tibiae either furnished with apical 

 spines on each side, or only on the inner side. 

 Tribe 6. Conocephalides. (Fig. 189, Copio- 

 piliora coniuta.) 

 9'. Posterior tibiae furnished above with an 

 apical spine placed only on the outer side. 

 Tribe 7. Tympanophorides. 

 8'. Posterior tibiae without apical spines. Tribe 8. 

 Sagides. 

 6'. Anterior tibiae furnished with an apical spine on the 

 inner side.'' 



^ This diagnosis is an attempt to express in something approaching an exact 

 manner the distinction of the flattened from the arched or convex head. 

 - Scrobes are the depressions in which the antennae are inserted. 

 ' There are unfortunately a few exceptions in the case of this character. 



