WHEELER, NORTH AMERICAN ANTS 347 



the posterior corners of the head. Thorax narrower than the head, broader in 

 front than behind, scarcely compressed laterally, in profile feebly arcuate 

 above, the pro- and mesonotum and base of the epinotum subequal, flattened, 

 separated by pronounced sutures ; the base of the epinotum somewhat longer 

 than the sloping, straight declivity with which it forms an obtuse angle. 

 Petiole rather high, in profile convex in front, flattened behind, with rather 

 blunt border ; seen from behind, narrow below, expanded above, with broadly 

 rounded upper border, feebly notched in the middle. Gaster of the usual 

 shape. Legs rather short, with stout femora ; tibise without rows of bristles 

 on their flexor surfaces. 



Mandibles lustrous or somewhat shining, very finely striated, with scattered, 

 coarse punctures towards their inner borders. Head, thorax and antennae 

 opaque or subopaque, finely and densely punctate. Cheeks and clypeus also 

 with scattered, somewhat elongated, piligerous foveolai. Petiole, gaster and 

 legs more shining, rather coarsely and transversely shagreened, with scattered 

 piligerous punctures. 



Hairs on the body rather abundant, delicate, short, erect and sordid white ; 

 absent on the sides and posterior corners of the head, short and obtuse on the 

 clypeus and cheeks ; absent on the scapes, except at their tips. Legs with very 

 short, sparse, oblique hairs ; femora with a row of long, erect hairs on their 

 flexor surfaces. Pubescence extremely short and sparse, visible only on the 

 autennal scapes, posterior portion of the head and basal gastric segment. 



Color black; mandibles, clypeus, cheeks, antennae, tibiae, tarsi and tips of 

 femora ferruginous or dark red. 



Worker minor. Length, 4-5 mm. 



Head resembles that of the worker major, but is smaller, with straighter 

 sides, more converging anteriorly. Eyes more convex. Autennal scapes reach- 

 ing about one-third their length beyond the posterior corners of the head. 

 Like the worker major in sculpture, pilosity and color, except that the red 

 coloration of the head is confined to its anterior border. There are no foveolae 

 on the cheeks and clypeus. The hairs on the body are also shorter and less 

 abundant. 



Described from numerous specimens taken by myself on the bark of 

 old mesqiiite (Prosopis velutina) trees at Tucson, Arizona. 



This subspecies differs from the typical mina first described by Forel 

 from Cape St. Lucas at the tip of Lower California and subsequently 

 redescribed from the same locality as C. erythropus by Pergande, in the 

 following characters : The clypeus of the worker major is distinctly cari- 

 nate, the piligerous foveolae on the cheeks and clypeus are much smaller, 

 shallower and less abundant, the punctures on the gaster are smaller and 

 sparser, there are no erect hairs and long pubescence on the antennal 

 scapes, except at their extreme tips, none on the sides and posterior 

 corners of the head, and the hairs on the thorax, petiole, gaster and legs 

 are much shorter, more delicate and much less abundant. These differ- 

 ences are shown by comparison of zuni with two major worker cotypes of 



