356 INSECTA. 



body is divided into fifteen semi-annuli, each bearing a pair of feet, termi- 

 nated by a very long, slender, multi-articulated tarsus; the last pairs are more 

 elongated; the eyes large and compound. 



Their antennae are slender and tolerably long; the two palpi salient and 

 furnished with small spines. Tlie body is shorter than in the other genera 

 of the same family, and the joints of their feet are proportionably longer. 

 They are extremely agile animals, and frequently part with some of their 

 feet when seized. 



LiTHOEiTJS, Leach. 



The stigmata lateral; body divided above and beneath into a similar 

 number of segments, each bearing a pair of feet; the superior plates alter- 

 nately longer and shorter, and overlapping each other close to the extremity. 



The others have at least twenty-one pairs effect, and the segments both 

 above and underneath are equal in size and number. 



ScoiopENDiiA, Lin. 



Those which form the two feet that immediately follow the two hooks 

 forming the exterior lip, present but twenty-one pah's, and whose antennae 

 have seventeen joints, constituting the genera Scolopendra and Crytops of 

 Leach. There are eight distinct eyes, four on each side in the first, and 

 that in which tlie largest species are found; in the second, they are null or 

 but very slightly visible. 



ORDER II. 



THYSANOURA, 



This order consists of apterous Insects, supported by six feet, 

 that experience no metamorphosis, and have, in addition, particular 

 organs of motion either on the sides or the extremity of the abdomen. 



FAMILY I. 



LEPISMEN^, Lat. 



Setiform antennas divided from their origin into very numerous 

 and small joints; mouth furnished with very distinct and salient 

 palpi; each side of the under part of the abdomen provided with a 



