98 THE AMERICAN NATURALIST. [Vor. XXXVI. 
4. Epinotum unarmed . . ORA P 
5. Head finely and densely rugose, ruga but little divergent posteriorly, 
without or with very indistinct interrugal sculpture . . 7 a—e 
6. Head less densely rugose, rugæ very distinctly divergent debtor, 
interrugal sculpture distinct, consisting of dense foveolate punctures 8 
7 a. Head, thorax, and legs black; d postpetiole, and gaster red. 
(Mexico.) . . P. barbatus F. Smith ('58, p. 130) 
. Cephalic ruge der "id denser, dus ferruginous red throughout. 
(Mex, Test, Ind; Ter, Ark, 
rs harhat, var. pee Ae Buckley ('61, p. 445) 
7c. Head and thorax brownish red, gaster in part or entirely brown. 
Rugosity as in 7 è or somewhat stronger. (Tex., Col.) 
P. barbatus, var. fuscatus Emery (94, p. 309) 
7d. Rugosity a little coarser than in 7 æ; head, thorax, and legs black, 
petiole and postpetiole brown, abdomen red, node of petiole longitu- 
dinally rugose. (Marfa, Tex.) . P. barbatus, var. marfensis n. var. 
. Head and thorax much more coarsely rugose than in 7 a-d. Ruge 
irregular in direction on the pro- and mesonotum, on the other regions 
transverse. Petiole rather strongly and irregularly rugose; its ante- 
rior stem-like portion shorter than in P. barbatus ; postpetiole rugose- 
punctate. (Cal) . P. barbatus, subsp. rugosus Emery ('94, p. 309) 
8. Head in. iront rugose, the rugæ distinctly divergent posteriorly, 
interrugal spaces densely fov: eolate punctate 9 
9. Lower surface of petiole without a distinct tooth ; intraspinal TERE 
of epinotum rugose, scarcely shining. . Io a-ó 
104. Head opaque, interrugal punctures distiuct. (Col, New Mex., 
Utah, Ariz, Nev., Wyo., Mont, Kans., Neb., Honolulu.) 
P. occidentalis Cresson ('65, pp. 426, 427) 
10 6. Head more shining, interrugal punctures more indistinct; petiole less 
opaque than in toa. (S. Cal. 
P. occidentalis, vat. subnitidus Emery ('94, p. 310) 
11. Petiole with a distinct tooth below; infraspinal concavity of epinotum 
shining, without ruga. (Cal) . P. subdentatus Mayr. (O, p. 971) 
12. Interrugal spaces of head rather indistinctly and oe punctate. 
Workers monomorphic . . . inåt 
13 a. Color yellowish red, stem of RS about ‘Ge same birth as its 
nodal portion ; postpetiole as high as long. (Cal, Lower Cal.) 
. californicus Buckley ('66, p. 236) 
13 À. sow red than 13 æ; apical third or more of gaster more or less 
black; petiole and postpetiole often brown, the former slender, its 
digit and less erect, with rounder or but slightly pointed apex. 
ow Cal.) 
> 
7 
“I 
n 
P. californicus, var. apens Pergande (93, p. 33) 
"ne Dee red, gaster brown except at the base; stem of petiole 
—— key very long nodal portion, which oe above ; 
