1-28 



Guide to Rfvriopoda. 



Table-case approximately upon alternate segments, the terga without stigmata 

 No. 2S. Ijeing greatly reduced in size. 



The young, upon hatching, liave only seven pairs of legs, the 

 remaining eight being added with successive moults. 



The Lithobiomorpha are swift-footed centipedes, which live 

 under stones or fallen tree-trunks, and feed upon worms, insects, 

 etc. They do not attain to any great size. 



There are about half-a-dozen British species of Lithohins ; 



perhaps the commonest of them is 

 Liiliolriiis forficatjis. 



Sub-class 

 ANARTIOSTIGMA. 



The normal tracheal system is 

 replaced in the Anartiostigma by a 

 series of median dorsal pulmonary 

 sacs, furnished with tubes dipping 

 into the pericardial space, and open- 

 ing each by a single stigma which 

 results from the upw^ard migration 

 and coalescence of the normal pair 

 of stigmata upon the first, third, fifth, 

 eighth, tenth, twelfth, and fourteenth 

 segments. The remaining segments 

 do not bear stigmata, and their dorsal 

 plates are reduced or absent, that of 

 the seventh disappearing completely. 

 The antennae are very long and 

 filiform ; the legs, of which there are 

 fifteen pairs, as in the Lithobio- 

 morpha, are also very long, and have 

 the terminal segments many-jointed. 

 The Sciitigcridae (Fig. 90), the 

 only family of the Sub-class, reach 

 their greatest size in the tropics, and are quite unknown in north 

 temperate and Arctic countries of the world. INIost of the 

 members of the order are of rather small size, but one or two of 

 the Oriental species (Scutigcra lo)u/icornis, etc.) reach a length of 

 several inches. They live on insects, and are remarkable for 

 their extreme swiftness of foot. They also have a habit, when 

 pursued or seized, of dropping their legs. Hence it is exceedingly 

 difficvilt to capture imdamaged specimens. 



Fig. 90. 



Scutigera (Ccrmatia) forceps (after 

 KiDgsley). 



