394 INSECTA. 



usually very large, and all the joints of the tarsi are entire ; the first, much 

 shorter than the following ones, is scarcely visible at the first glance, and the 

 last is most commonly terminated by a simple hook. 



They are found on the ground under the debris of vegetable matters ; some 

 inhabit certain ant-hills. 



Those which have eleven joints in the antenna; form the genus 



PSELAPHUS, Herbst. 



In the last of the Pselaphii, we observe this peculiarity their antenna; con- 

 sist of but six joints, or even one. They form the genus 



CLAVIGER, 



Where the antenna- consist of six distinct joints. These insects have no 

 apparent eyes. The maxillary palpi are very short, without distinct articula- 

 tions, and with two terminal hooks. The two first joints of the tarsi are very 

 short ; the third and last is very long, with a single hook at the extremity. 



These Pselaphii are found under stones in barren localities, and even in the 

 hills of certain small, yellow ants. 



ORDER VI. 



ORTHOPTERA *. 



IN the insects of tlu's order, we find the body generally less indurated than 

 in the Coleoptera, and soft, semi-membranous 

 elytra furnished with nervures, which, in the 

 greater number, do not join at the suture L in a 

 straight line. Their wings are folded longitudi- 

 nally, most frequently in the manner of a fan, and divided by membranous 

 nervures running in the same direction. The maxilla.* are always terminated 

 by a dentated and horny piece covered with a galea, an appendage corre- 

 sponding to the exterior division of the maxillae of the Coleoptera. They 

 have also a sort of tongue or epiglottis. 



The Orthoptera undergo a semi-metamorphosis, of which all the mutations 

 are reduced to the.growth and development of the elytra and wings, that are 

 always visible in a rudimental state in the nymph. As both this nymph and 

 the larva are otherwise exactly similar to the perfect insect, they walk and 

 feed in the same way. 



The mouth of the Orthoptera consists of a labrum, two mandibles, as many 

 maxillie, and four palpi ; those of the jaws always have five joints ; whilst the 



Straight-winged. 



