406 



ARACHNID A 



D. whitei (Gervais). Color yellow or brown; terminal joint of foot 

 with a row of about 7 spines running up from the claw; teeth of comb 

 12 to 18; length 5 cm.: Texas to California. 



Family 3 CENTKUKIDAE. 



Sternum small and triangular, the sharp end in front ; a spur on the 

 under side of the unmovable finger of the mandible : 4 genera and about 

 50 species, many American. 



Centrurtjs Ehrenberg (Fig. 640). The oblique rows of teeth on 

 the finger of the pedipalp have on each side a parallel row of minute 

 teeth; under the sting may be a spine: 15 American species. 



C. carolinianus (Beauvois). Color yellowish, with small spots, often 

 joined into 2 longitudinal stripes; length 7 cm.; teeth of comb, 19 to 25: 

 southern states. 



Order 2. PALPIGRADI.* 



Minute arachnids with a segmented abdomen, from the hinder end 

 of which a long segmented caudal filament 

 with segmental bristles projects; mandible 

 long and chelate; pedipalps and the 4 pairs 

 of legs rather long and slender; no eyes; 

 cephalothorax of 3, abdomen of 11 segments : 

 1 genus with a few species, which have 

 been found in Italy, Siam, Paraguay, and 

 Texas. 



KcENENiA Grassi. With the characters 

 above mentioned: 2 American species. 



K. wheelerif Riicker (Fig. 641). Length 

 with filament up to 2.5 mm.; color white; 



3 pairs of eversible lung sacs on segments 



4 to 6: under stones in moist places near 

 Fig. 641 — Kcenenia wliecleri . 



(Wheeler). Austin, Texas. 



Order 3. PEDIPALPI.t 



Cephalothorax separated by a constriction from the abdomen, which 

 is 11 or 12-jointed; last 3 pairs of legs used for walking; in the first 



* See "Palpigradi und Solifugae," by K. Kraepclin, Das Tierreich, 1901. 



t See "A Singular Arachnid," etc., by W. M. Wheeler, Am. Nat., Vol. 34, p. 8.37, 

 1900. "The Texas Kcenenia," by Augusta Riicker, Am. Nat, Vol. 35, p. 615, 1901. 

 "A New Kcenenia from Texas," by san:e, Q. J. M. S., Vol. 47, p. 401, 1903. 



% See "On the Pcdipalpi of North America," by H. C. Wood, Jour. Acad. Nat. Sci., 

 Phila., Vol. 5, p. 357, 1SG3. "Scorpioncs und Pedipalpi," by K. Kraepelin, Das Tier- 

 reich, 1899. "Synopsis of North America Pedipalpi," by N. Banks, Am. Nat., Vol. 34, 

 p. 421, 1900. 



