436 FR0CEEDINQ8 OF THE NATIONAL MUSEUM. vou 54. 



15. (o) Mandibles rounded with apical tooth 16. 



(b) Mandibles emarginate at apex with strong outward curved tooth at 



inner angle and outer angle rounded ; spiracle slightly convex but not 

 prominent ; base of head 0.56 to 0.65 as wide as cephalothorax at 

 spiracles ; base of cephalothorax 0.71 to 0.78 breadth at spiracles ; 

 length of cephalotliorax 1.02 to 1.18 breadth at spiracles (Stylops, 

 group 7) erigeniae. 



16. (a) Base of head 0.64 as wide as cephalothorax at spiracles; base of cepha- 



lothorax 0.79 breadth at spiracles; length of cephalothorax 1.03 

 breadth at spiracles; spiracles barely marginal {Stylops, group 

 8) hippotes. 



(b) Base of head 0.55 as wide as; cephalothorax at spiracles; base of 



cephalothorax 0.77 breadth at spiracles ; length of cephalothorax 1.06 

 breadth at spiracles ; spiracles laterally slightly convex but not promi- 

 nent (Stylops, group 8) nasoni. 



17. (a) Mandibles two-angled at apex and slightly emarginate between, not 



distinctly toothed; base of head 0.66 as wide as cephalothorax at 

 spiracles ; base of cephalothorax the same ; length of cephalothorax 

 1.03 breadth at spiracles; spiracles barely marginal {Stylops, group 



9) stvenki. 



(6) Mandibles toothed at apex and angled on outer side 18. 



18. (a) Cephalothorax as long as broad; spiracles barely marginal {Stylops, 



group 10) claytonme 19. 



(&) Cephalothorax longer than broad ■« 20. 



19. Varieties of S. claytoniae; base of cephalothorax 0.68 breadth at 



spiracles, 

 (a) Mandibles rounded witli apical tooth and slight angle on outer side; 



base of head 0.54 as wide as cephalothorax at spiracles. 



var. claytoniae. 

 (ft) Mandibles subquadrate with tooth near inner apical angle and with 



strong angle near middle of outer side; base of head 0.58 as wide as 



cephalothorax at spiracles var. imitatrix. 



(c) Mandibles strongly two-toothed; base of head 0.64 as wide as cephalo- 



thorax at spiracles var. vierecki 



20. (a) Lateral angle of mandible not toothlike 21 



(&) Lateral angle of mandible toothlike and subbasal 22 



21. (a) Base of head 0.56 to 0.59 as wide as cephalothorax at spiracles; base ot 



cephalothorax 0.66 breadth at spiracles ; length of cephalothorax 1.07 

 breadth at spiracles {Stylops, group 11) bruneri. 



(&) Base of head 0.59 as wide as cephalothorax at spiracles; base of cepha- 

 lothorax 0.70 breadth at spiracles ; length of cephalothorax 1.09 

 breadth at spiracles {Stylops, group 11) oklaJiomae. 



(c) Base of head 0.60 as wide as cephalothorax at spiracles; base of cepha- 

 lothorax 0.80 breadth at spiracles; length of cephalothorax 1.06 

 breadth at spiracles {Stylops, group 11) salictariae. 



{d) Base of head 0.62 as Mide as cephalothorax at spiracles; base of cepha- 

 lothorax 0.73 breadth at spiracles; length of cephalothorax 1.04 

 breadth at spiracles {Stylops, group 11) andrenoides. 



(e) Base of head 0.61 as wide as cephalothorax at spiracles; base of cepha- 

 lothorax 0.75 breadth at spiracles ; length of cephalothorax 1.08 

 breadth at spiracles; outer apical angle of mandible strongly rounded, 

 apex emarginate between angle and tooth {Stylops, group 11). 



medionitaiu. 



