CHAP. XVI 



PALPIGRADI SOLIFUGAE 



423 



genital operculum is complicated, and is situated beneath the 

 second abdominal segment. 



Since 1885 several other species have been discovered in 

 various parts of the world. Two American 

 forms possess three pairs of lung-sacs on 

 segments 4, 5, and 6 of the abdomen. 

 Eucker l has suggested for them the 

 generic name of Prokoenenia, including 

 P. wheeler i, Eucker, from Texas, and P. 

 chilcnsis, Hansen, from Chili. The others, 

 styled by that author Eulcoenenia, have 

 no lung-sacs. There are about ten 

 species, mostly from the Mediterranean 

 region, but E. augusta, Hansen, is found 

 in Siam, E. florenciae, Eucker, in Texas, 

 and E. grassii, Hansen, in Paraguay. 



Order V. Solifugae (Solpugae). 



Illlli'll rill,! i 



(After Hauscn.) 



Arachnids, ?> if//, flic /ttsf //</vr 

 segments of the cepliKlothorn,,; free and tin- 

 abdomen segmented. The chelicerae are 

 largely developed and chela/', <ni<i tin- 

 pedipalpi are leg-Wee, possessing fir mi mil 

 sense-organs. 



The Solifugae are, in some respects, FIG. 216. K,-, ; 

 the most primitive of the tracheate 

 Arachnida. Their general appearance; is 

 vi -ry spider-like, and by the old writers they are uniformly 

 alluded to as spiders. The segmented body and the absence of 

 spinning organs, however, make tln-m readily distinguishable on 

 careful inspection. They are for the most p;irt imctm n.-il 

 creatures, though some seem to rove about by day, ;md ;ire even 

 called "Sun-spiders" ly tlie Spanini'ds. The niglit-lovin-- spei 

 are attracted by light. They are, as a rule, exceedingly hairy. 

 Some are extremely active, while the short- le^jed forms (e.g. 

 Rhagodes, see p. 429) move slowly. They are capable of pro- 

 ducing a hissing sound by the rubbing together of their chelicnar 

 Only the last three pairs of legs are true ambulatory organs, the 



1 Quart. J. Ml<-r. Sci. xlvii. I'.KU. p. 215. 



