486 



INSECTA. 



have only fifteen* pairs of feet; and their body, when seen from above, exhibits fewer segments than 

 when seen from beneath. 



Sciitigera, Lamarck (Cirmatia, Illigcr), forming; a genus very distinct from the rest of this family, has the body 

 covered by eight shield-like plates, beneath each of which M. de Serrcs has observed two pneumatic sacs, or vesi- 

 cular tracheae, communicating with tubular, lateral, and inferior trachea;. The under side of the body is divided 

 into fifteen semi-segments, each bearing a pair of legs terminated by a very long, slender, and multiarticulated 

 tarsus : the hind pairs are very long. The eyes are large and facetted. They form the passage from the preceding 

 family to the present. They are very active, and often lose some of their legs when touched. The French 

 species {Scolopendre a vingUhuit pattes, Geolf., — S. coleoptrata, Panzer?) hides itself under the beams and joists 

 of the wood-work of houses. S. longicornis, Fabr., and other species. 



Lithobius, Leacli, has the spiracles lateral ; the body di- 

 vided, both above and below, into the same number of seg- 

 ments, each of which bears a pair of legs ; and the dorsal 

 plates are alternately longer and shorter. Scolopendra forci- 

 pata, Linn., and others described by Fabricius, Panzer, and 

 Leach (Zool. Miscel. vol. iii.) 



The others have at least twenty-one pairs of feet, 

 and the segments are of equal size and number, both 

 above and beneath. 



Scolopendra proper, Linn. Those species which have only twenty-one pairs of feet, after the two 

 hooks forming the lower lip and the antennas, and have seventeen joints, form Leach's genera Scolo- 

 pendra and Cryptops. In the former, comprising the largest species, the eyes are distinct, eight in 

 number, four on each side. In the latter, the eyes are wanting, or very slightly perceivable. The 

 southern departments of France, and other countries of the south of Europe, produce a species (Scot, 

 cingtdata, Latr.) which is occasionally nearly as large as the common species of the Antilles, but 

 having the body flatter. Also, Scol. morsitans, Linn. ; Scol. gigantaa, Linn. ; and others described 

 by De Geer, Leach, &c., but incompletely. 



Cryptops has the joints of the antennae more globose, subconic, and the two hind legs more slender. 

 Two species, found near London — C hortensis and Savignii, Leach. 



GeopMlus, Leach, has more than forty-two legs, often much more numerous ; antenna; 14-jointed, 

 not so slender at the tip ; body proportionately longer and narrower ; eyes scarcely distinct. Some 

 species are electrical (Scol. clectrica, Linn.) ; and others, especially described by Leach in Zool. 

 Miscell. vol. iii., Scol. phosphorea, Linn., fell from the clouds upon a vessel at the distance of one 

 hundred miles from the main land. 



Kig. 46. — a, Lithubius forcipatus ; b, Geophilus longicorois 



Fig. 46. — Scolo- 

 pendra. 



[Dr. Leach published a valuable memoir upon these animals, illustrated by figures, in the third 

 volume of the Zoological Miscellany. M. Brulle, also, in the French national work upon the Morea, and 

 Koch, in Schaffer's continuation to Panzer, have published various detached species. Say described 

 many American species ; and M. Gervais has also published several memoirs on this tribe in the Magasin 

 de Zoologie, the Annals of the French Entomological Society, and especially in the Annates des Sciences 

 Naturelks for January, 1837, in which he has given a complete revision of the order, and has made 

 some observations on the young state of some of these animals, and the changes they undergo.] 



[In the Bulletin of the Imperial Academy of St. Petersburg, tom. i.. No. 23, p. 182, Brandt has 

 established another order amongst the Myriapodous Insects, dividing them into two orders: — 1. Gnatho- 

 gena;, including all the previously known Myriapoda, with the two groups, Chilopoda and Chilognatlia; 

 and, 2. The Siphonozantia, which have the parts of the mouth produced into a proboscis. This new 

 order is divided into two sections and three genera : namely, Polyzonium, Brandt ; type, P. germani- 

 cum, found in Germany ; and Siphonatus and Siphonophora, founded upon Brazilian species.] 



THE SECOND ORDER OF INSECTS,- 



THYSANOURA,— 



Comprises those apterous insects furnished with six legs, which do not undergo a metamor- 

 |)hosis, and have, moreover, at the sides of tlie body, or its extremity, pecidiar organs of 

 locomotion. 



* LeaLli cuuulb Iwo more pair.s, because he includca aliu the palpi, and iiouKcii fett of llie head, in llie number. 



