1NSF.CTA. 



Their antenna are slender and tolerably long ; the two palpi salient and fur- 

 nished with small spines. The 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. 



LITHOBIUS, Leach. 



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

 of segments, each bearing a pair of feet ; the superior plates alternately longer 

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



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

 above and underneath are equal in size and number. 



RcOLOPENDRA, I .i It IHl'lls. 



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

 forming the exterior lip, present but twenty-one pairs, and whose antenna: have 

 seventeen joints, constituting the genera Scotopendra and Crytops of Leach. 

 There are eight distinct eyes, four on each side in the first, and that in which 

 the largest species are found ; in the second, they are null or but very slightly 

 visible. 



The southern departments of France and other countries of the South 

 of Europe produce a species nearly as large as the common Scolopendra of the 

 Antilles, but having the body more flattened. This is the S. cinjulata of Linnaeus. 

 The species which form the genus Crytops, Leach, have rougher antenna? than 

 the Scolopendrce ; the two posterior feet are also more slender. 



ORDER II. 

 THYSANOURA. 



THIS order consists of apterous Insects, supported by six feet, that expe- 

 rience no metamorphosis, and have, in addition, particular organs of motion 

 either on the sides or the extremity of the abdomen. 



FAMILY I. 

 LEPISMENvE, Lalreille. 



SETIFORM antennae 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 range of moveable appendages, in 

 the form of false feet; abdomen terminated by articulated setse, three of which 

 are the most remarkable; body always^covered with small shining scales. 



It comprises but one genus, the 



