1908.] NATURAL SCIENCES OF PHILADELPHIA. 223 



wider than long with the guide more or less strongly arched at middle, 

 and with the lateral depression, relativel}^ wide and short, tending to 

 subcircular; the lateral ridges commonly low at middle (PI. XX, 

 fig. 2. avara; PI. XX, fig. 6, cinerea). In the male palpal organ the 

 proximal limb of scopus is more strongl}- developed, being more or 

 less elongate and bent out vertically as a conspicuously salient 

 process (PI. XX, fig. 1, avara). Some but not all species in the group 

 have the stout spine, normally present alcove at proximal end of the 

 tibiae of the third and fourth legs in Lycosa, replaced by a very elon- 

 gate, basally stout bristle clearly stouter at base than surrounding 

 haii"s, spine-like, but distally gradually extending into a long fine awn. 

 Through some forms of this group a close approach is made to Allocosa, 

 which may ultimately have to be withdrawn into the present genus. 



Key to Species of Lycosa. 



1. Venter of abdomen black in front of genital furrow and in a spot at 



base of spinnerets, elsewhere pale brown, . coloradensis Bks. 

 Not so, . . . . 2. 



2. Lower margin of furrow of chelicera armed with but two teeth, . 3. 

 liOwer margin of furrow armed with three teeth, 4. 



3. Anterior lateral eyes their diameter from front margin of clypeus, 



kocJdi (Keys.). 



Anterior lateral eyes once and one-half their diameter from front 



margin of clypeus heanii Em. 



4. No spine at all above on tibiae of legs III and IV, 5. 



Spine at middle or both at middle and at proximal end on tibiae 



of legs III and IV, 6. 



5. Dorsum of abdomen with a distinct median dark band along its 



entire length ; light median band on cephalothorax, arenicola Sc. 



Dorsum of abdomen without such a dark band; cephalothorax 



without distinct markings, fatifera Htz. 



6. No true stout spine at base above on tibiae of legs III and IV, 



replaced by a basally stout, apically slender and pointed, 



elongate bristle, 7. 



A true robust spine at base above on tibiae of legs III and IV, 10. 



7. Tibia -1- patella of legs I^^ less than 3 mm. long, floridiana (Bks). 

 Tibia + patella of legs IV near 4 mm. long or longer, .... 9. 



9. Eyes upon a black patch ; legs not marked with dark annuli, 



cinerea Fab. 

 Eyes not upon a black patch ; legs marked with dark annuli, 



rubicunda. 



10. Cephalothorax with a light median longitudinal stripe which is very 



narrow or line-like anteriorly and which extends forward to or 



between eyes of second row, 11. 



Cephalothorax either without a median band or with a band 

 which is as wide or nearly as wide as the third eye row, . , 18. 



