450 ARTHKOPODA. 



second ( thoracic ' somites, a condition which deserves embryologi- 

 cal investigation. The abdomen consists of nine or ten somites, 

 and the head bears two ocelli. 



As the name implies, the Solpugidae are nocturnal, living by day in 

 holes in the sand and searching for their prey at night. In the Old World 

 they are reputed as poisonous, but no poison glands occur. "Warmer parts 

 of U. S. Solpuga,* Galeodes* Datames * (fig. 464). 



FIG. 464. FIG. 465. 



FIG. 464. Datames formidibilis* (After Putnam.) 



FIG. 465. Chelifer bravaisi. (From Schmarda.) 1, cheliceree; 8, pedipalpi. 



Order V. Pseudoscorpii. 



These small forms resemble the true scorpions in the chelate 

 cheliceraB and pedipalpi (fig. 465), and in the abdomen joined by 

 its whole breadth to the thorax. They differ in the lack of post- 

 abdomen and sting. They breathe by tracheae; have from two to 

 four ocelli, and spinning glands opening on the second abdominal 

 somite. 



These animals, 2-3 mm. long, live in moss, etc., and among old and 

 dusty books, where they feed on mites and minute insects. Their bodies 

 are flattened and they run side wise. Chelifer,* Obisium,* Chernes.* 



Order VI. Phalangida. 



The abdomen in the harvestman, or 'daddy long legs/ is less 

 evidently segmented than in the forms already mentioned, nor is 

 it sharply distinct from the cephalothorax. The small body bears 

 four pairs of exceedingly long legs; the cheliceraB are drawn out 



