1908.] NATURAL SCIENCES OF PHILADELPHIA. 301 



forms in case of danger dive readily beneath the surface of the water 

 and hide under stones, leaves,, etc., at the bdttom. The cocoon is 

 carried about attached to the spinnerets, though when the females are 

 at rest it is commonlj^ held in the chelicerse. The cocoons are clear 

 white in color and spherical in shape, marked at the equator by a seam 

 less strong than that on the cocoons of Pardosa. The female con- 

 structs a temporary retreat under stones and other suitable places, 

 spinning a small irregular web of very delicate texture. The greater 

 length of the superior spinnerets would seem to be associated with 

 this web-spinning habit. 



Key to Species of Pirata. 



1. Lower margin of the furrow of the chelicerae armed with but two 



teeth, 2. 



Ivower margin of furrow armed with three teeth, 3. 



2. Cephalothorax less than 2 mm. long, minutus Em. 



Cephalothorax 3 mm. or more long, marxi Stone. 



3. Cephalothorax with no submarginal light stripes, . monianus Em. 

 Cephalothorax with submarginal light stripes 4. 



4. Cephalothora^c less than 2 mm. long, or at most not longer, . 5. 

 Cephalothorax much more than 2 mm. long, 6. 



5. All joints of legs except tarsi distinctly ringed with black (female), 



aspirans Chamb. 



Femora dark at distal ends, other joints of legs light, not at all 



marked with dark, Jnimicolus Mtg. 



6. Cephalothorax in life or when dry showing on each side a marginal 



stripe of bright white hair, 7 



Cephalothorax showing no such stripe, insularis Em. 



7. A black marginal stripe below each pale lateral stripe, 



piratica utahensis, new var. 

 No such black marginal line, fehriculosa (Beck.). 



The key above does not include prodigiosa Keys, or hilohatus TuUg. 



Firata minutus Emerton, 1885. 



(Trans. Conn. Acad. Sci., 6, p. 493, PI. 48, figs. 10-lOc.) 

 Female. — Sides of cephalothorax dark brown to gray-brown; a yellow 

 median stripe of more or less greenish hue which begins caudally 

 as a narrow line, but expands continuously forward to the eye region, 

 continuing as a narrow stripe on each side below eyes to the clypeus as 

 usual; within the median light band are two dark lines or narrow 

 stripes extending backward from eyes of third row and uniting together 

 into one line at the dorsal groove, forming thus the typical V-shaped 

 mark; a marginal light strij^e on each side with uneven upper border, 

 20 



