518 



MYKTAPODA. 



FIG. 423. Embryo of Stroiigylosoma (after E. 

 Metschnikoff ) . 



their eggs in earth. The just-hatched young often pass through 

 a metamorphosis, having at lirst only three or seven pairs of 

 legs in addition to the antenna?, and a few somites without limbs 

 (fig. 423). The young animals undergo numerous moults, and 



gradually increase in size: the 

 extremities sprout out on the 

 somites, which are already 

 present. New somites are 

 constricted oft' from the termi- 

 nal one until the full number 

 is completed ; the number of 

 ocelli and of the joints of the 

 antenna? is increased, and the 

 resemblance to the sexual animal is gradually perfected. In other 

 cases (Scolopendra, GeopldlidcK] the embryo already possesses the 

 full number of appendages. 



Order 1. CHILOPODA.* 



Myriapoda of usually flattened form, with long many-jointed 

 antennce, and mouth parts adapted for predatory habits, with only one, 

 pair of appendages to each segment. 



The body is long and usually flat- 

 tened. The chitinous exoskeleton 

 is hardened on the dorsal and ven- 

 tral surface of each somite, consti- 

 tuting the tergal and sternal plates, 

 while on the sides of the somites it 

 remains soft. In certain forms 

 some of the terga develop to large 

 shields, which over-lap the smaller 

 terga of the intermediate somites 

 (fig. 424). The number of legs is 

 never greater than that of the sepa- 

 rate segments, a single pair only 

 being developed on each segment. 

 The antenna? are long and many- 

 jointed, and are inserted beneath the 

 frontal margin. The eyes are simple 

 or aggregated ocelli, except in the genus Scutigera which has facetted 



FIG. 21.LitJwIjiHs forficafits (after C. 

 L. Koch) . Kf, Poison claws. 



* Newport, "Monograph of the Class Myriapoda. order Chilopoda,'' Lhinfean 

 x, XIX. 



