Crustacea 239 



quite large, but none brightly colored. A common species is 

 Lycosa carolinensis, the female reaching a length of over an inch, 

 mouse-color above, largely black beneath. In the breeding season 

 the egg-bag is carried, attached beneath the abdomen. About 

 the University campus at Boulder, and elsewhere, one may find 

 under rocks a fat, round-bodied, jet-black spider, with a little 

 bright red spot at the tail end. This is Lathrodectus mactans of 

 Fabricius, extending from the temperate zone to the tropics, and 

 famous for its poisonous bite. There is a very interesting small 

 spider (Phrurolithus) which lives under rocks with ants of the 

 genus Crematogaster. In the Eastern States both ants and 

 spiders are black, but at Boulder the ant is a different form, 

 having a red thorax, so the spiders possess a red cephalothorax to 

 correspond. 



HARVEST- SPIDERS (PHALANGIDA) 



These animals, sometimes called daddy-long-legs, have ex- 

 tremely long legs, and may be mistaken for true spiders. They 

 are, however, easily separated by the form of the body, the 

 cephalothorax not being separated from the abdomen by any 

 waist-line or constriction. Thus they have the outline of Humpty- 

 Dumpty. We have several species, one of the most curious being 

 a small red one (Sclerobunus robustus of Packard), found under 

 stones in the mountains. 



PSEUDOSCORPIONS (PSEUDOSCORPIONIDA) 



Like very minute scorpions, but without any tail. They 

 may be found under rocks and beneath the bark of trees. 



SCORPIONS (SCORPIONIDA) 



Easily known by the long tail, at the end of which is the 

 sting. The group is one of enormous antiquity, older than any 

 known insects. 



SOLPUGIDS (SOLPUGIDA) 



Peculiar pale-colored soft animals, resembling spiders, but 

 the elongated abdomen is distinctly segmented. They are 



