INSECTA. 351 



and of which the first, and in several even the second, seem to form 

 a part of the mouth. They are apterous( 1). 



In the second or the Thysanottra, there are six legs, and the 

 abdomen is furnished on its sides with movable parts, in the form 

 of false feet, or terminated by appendages fitted for leaping. 



In the third or the Parasita, we find six legs, no wings, and no 

 other organs of sight than ocelli; the mouth, in a great measure, is 

 internal, and consists of a snout containing a retractile sucker, or in 

 a slit between two lips, with two hooked mandibles. 



In the fourth or the Suctoria, there are six legs, but no wings; 

 the mouth is composed of a sucker inclosed in a cylindrical sheath, 

 formed of two articulated portions. 



In the fifth or the Coleoptera, there are six legs, and four wings, 

 the two superior of which have the form of cases, and mandibles and 

 maxillae for mastication: the ioferior wings are simply folded cross- 

 wise, and the cases, always horizontal, are crustaceous. They ex- 

 perience a complete metamorphosis. 



In the sixth or the Orthoptera, there are six legs; four wings, 

 the two superior in the form of cases, and mandibles and jaws for 

 mastication, covered at the extremity by a galea; the inferior wings 

 are folded in two directions, or simply in their length, and the inner 

 margins of the cases, usually coriaceous, are crossed. They only 

 experience a semi-metamorphosis. 



In the seventh or the Hemiptera, there are six legs and four 

 wings, the two superior in the form of crustaceous cases, with mem- 

 branous extremities, or similar to the inferior, but larger and firmer; 

 the mandibles and jaws are replaced by setae forming a sucker, en- 

 closed in a sheath composed of one articulated, cylindrical or 

 conical piece, in the form of a rostrum. 



In the eighth or the Neuroptera, there are six legs, four mem- 

 branous and naked wings, and mandibles and jaws for mastication; 

 the wings are finely reticulated, and the inferior are usually as large 

 as the superior, or more extended in one of their diameters. 



In the ninth or the Hyhenoptera, there are six feet, and four 

 membranous and naked wings, and mandibles and jaws for mastica- 

 tion; the inferior wings are smaller than the others, and the abdo- 

 men of the female is almost always terminated by a terebra or sting. 



(1) Destitute of wings and scutellum. 



