5:2 cxsTcnopnoiiA. 



means of tracheae, which open to the exterior by four slit-like 

 openings between the first and second pair of thoracic appendages 

 and on the ventral surface of the abdomen. They live in warm, 

 sandy localities, especially of the Old World. They are nocturnal 

 in their habits, and are feared on account of their bite. 



Fam. Solpugidae. Solpnya (Galeodcs) arancoides Pall., found on the steppes 

 of the Volga and in South Russia. Other larger species are found in Africa, and 

 some forms are known in America. 



Class III, ONYCHOPHORA * (PROTOTRACHEATA). 



Tracheata with elongated vermiform body, two antennae, and short 

 paired imperfectly -jointed legs armed with claws. 



FIG. 414. Peripatuf capensis (after Moseley). 



The Onychophora, which are represented by the single genus 

 Peripatus, have a moderately elongated body, which is provided with 

 paired legs (from fourteen to more than thirty pairs), each armed 

 with two small claws (fig. 414). The head is distinct, and bears a 



pair of antennae and two simple 

 eyes. On its under surface the 

 mouth is placed beneath a large 

 projecting suctorial lip, and is fur- 

 nished with a pair of jaws armed 

 w T ith chitinous claws. On each side 

 of the mouth short, indistinctly 

 jointed oral papillae are attached to 

 the sides of the head. The nervous 

 system is distinguished by the re- 

 markable separation of its two 

 halves. The paired cerebral ganglion 

 gives off two nerve trunks, which indeed approach each other closely 



* E. Grube, " Ueber den Bau des Peripatus Edwardsii," Miillcr's Archir.. 

 1853. Moseley, "On the Structure and Development of Peripatus capensis," 

 Phil. Trans., 1875. [F. M. Balfour. " On the Structure and Development of Peri . 

 patus Capensis," Quart. Joiirn. of Mic. Science, 1883.] 



FIG. 415. Head of a Peripatus embryo 

 (after Moseley). An, Antennae; K. 

 jaws, anterior to which are the ecto- 

 derm thickenings, which will form the 

 brain. 



