CENTIPEDES 43 



legs is usually longer and stouter than the others, but may be 

 modified as antenniform tactile sense-organs as in the South 

 American genus Newportia. The terminal legs may be expanded 

 and leaf-like at the end, forming a stridulating organ as in the 

 large tropical African genus Alipes, or short, thick and armed with 

 a piercing claw used for holding food as in the American genus 

 Theatops. 



Some of the tropical species of Scolopendra are commonly six or 

 eight inches in length, while the largest, S. gigantea from tropical 

 America, measures as much as a foot. Many of these are attrac- 

 tively coloured in the living state. For example, the South African 

 Rhysida afra is a deep and striking shade of blue or blue with a 

 greenish tinge, S. morsitans has green crossbars on a yellow back- 

 ground, while S. cingulata is a beautiful olive green. This species 

 is distributed widely throughout the Mediterranean regions of 

 Europe, North Africa and the Middle East, but varies considerably 

 in size in diiTerent localities. African and Asiatic specimens may 

 reach a length of 18 cm when fully extended and have a yellow 

 body and blue hind legs. Unfortunately they all tend to fade to a 

 uniform dull brown colour when preserved. S. morsitans and S. 

 subspinipes have been transported all over the tropics by commerce, 

 but are unable to establish themselves in temperate latitudes. 

 Related genera are Ethmostigmus, which is abundant in Africa, and 

 Cormocephalus which is equally abundant in both the Ethiopian 

 and Indo-Australasian regions. Only three representatives of the 

 order occur in the British Isles, namely Cryptops hortensis, C. 

 anomalans and C. parisi. Of these the most common is the orange- 

 coloured C. hortensis frequently found in potting sheds and under 

 the bark of trees, etc. 



The order Craterostigmomorpha has been established for the 

 centipedes of the genus Crater ostigmus which is intermediate in 

 many points between the Scolopendromorpha and the Litho- 

 biomorpha, and, like many ancient arid annectant types, occurs in 

 Australasia. There are only 15 pairs of legs and sterna and the 

 spiracles are reduced to seven pairs as in the Lithobiomorpha, but 

 there are 21 tergal plates representing the somites of the leg- 

 bearing segments of the Scolopendromorpha. Unfortunately 

 nothing is known of the biology of these animals. 



