208 CENTIPEDES AND MILLIPEDES. 



The order Geophilomorpha, represented by the family Geophttidce, includes the 

 long worm-like centipedes, with the segments varying in number from thirty-nine 

 to over a hundred. There are no eyes, and the short thick antennae are always 

 composed of fourteen segments. Each segment of the body, with the exception 

 of the first and last, bears a pair of stigmata and is double, an anterior portion being 

 cut off by a distinct joint. The Geophilidce, which are distributed all over the world, 

 with the exception of the polar areas, are subterranean in their habits, burrowing 

 after the manner of earth-worms, upon which they almost wholly subsist. Two 

 exceptions, however, to this rule must be mentioned, namely, Linotcenia maritima 

 and Sckendyla submarina, both of which have been obtained upon the shores of 

 Western Europe, beneath stones at low-water mark. Although this is a strange 

 habitat for animals, air-breathing species typically terrestrial can withstand 

 immersion in sea- water for many hours, and in fresh water from one to two 



GEOPHILUS GRAPPLING WITH EARTH-WORM (nat. size). 



weeks. Many of the species emit a phosphorescent fluid from glands opening 

 upon the sternal surface of the segments. In Europe the time for the appear- 

 ance of the phenomenon is between the end of September and the beginning 

 of November. Although its import is not understood, it appears to be connected 

 in some manner with the mating of the sexes. A small reddish species (Linotcenia 

 crassipes) is the one most commonly found exhibiting this phosphorescence in 

 England. 



Remains of fossil centipedes referable to the existing groups occur in amber 

 beds belonging to the middle portion of the Tertiary period ; while mere aberrant 

 types have been discovered in the Palaeozoic rocks of the United States. 



To a certain extent, connecting the centipedes with the millipedes and insects, 

 is the class Symphyla, containing the single genus Scolopendrella. This is repre- 

 sented by minute pale-coloured creatures, with long thread-like antennae, fifteen 

 or sixteen body-segments, and twelve pair of legs, each of which is armed with 

 two claws. It further differs from the centipedes in having only two pairs of 

 jaws, as in the millipedes. Scolopendrella, which includes two British species, also 

 occurs in North America, India, and Sumatra. 



THE MILLIPEDES, Class Diplopoda. 



Although millipedes and centipedes were formerly united to form the class 

 Myriopoda, it has been discovered that the characters in which they resemble each 



