324 Bulletin American Museum of Natural History. [Vol, XXI, 



Adalc. — Length 9 mm. 



Head very small, barely half as broad as the thorax, rounded behind, with 

 short, flat cheeks, prominent eyes and ocelli. Mandibles and clypeus like those 

 of the worker; antennae long; scape but little thicker than the uniforinly 

 cylindrical funiculus; as long as the first and second funicular joints together; 

 first funicular joint more than half as long as the second; third to last joints 

 subequal, a little shorter than the second. Thorax very, robust, broadly 

 elliptical from above; mesonotum in profile high and arched. Petiole low and 

 rather thick, its edge broadly rounded and notched in the middle. Gaster very 

 short, convex above. Genital valves very large; outer pair broadly rounded 

 above, with a short, rounded inferior lobe; median pair produced behind into a 

 short, triangular, pointed process which has its dorsal margin broadly excised 

 at the base and the apical margin coarsely dentate. Legs slender. Wings long 

 (14 mm.). 



Body more opaque than in the worker and female, owing to the sharper 

 reticulation of the head and thorax. 



Hairs and pubescence tawny or golden, distributed as in the female ; except 

 that the antennal scapes bristle with numerous erect hairs. 



Body and appendages black, mouth-parts and inner genital valves yellowish. 

 Wings of the same color as in the female. 



Types from "Mexico," in the collection of Dr. Gustav Mayr of 

 Vienna. 



The above description is drawn from numerous workers collected 

 by Mr. C. H. Tyler Townsend on the volcano of Colima, Mexico 

 (7500 ft.), a dealated female from Mexico, received from Dr. Mayr, 

 and a winged female and a single male from Arizona (Am. Mus. Nat. 

 Hist. Coll.).- Forel records the species from Pinos Altos, Chihuahua, 

 and Ciudad in Durango, Mexico (8100 ft.). I have seen numerous 

 workers from the following localities: Canon City (5329 ft.) and 

 Cotopaxi (6371 ft.), Colorado (P. J. Schmitt, O. S. B.); Manitou 

 (6309 ft.). Garden of the Gods, and Cheyenne Cafion (7000 ft.), 

 Colorado; Paisano Pass (5079 ft.) and Ft. Davis (5400 ft.), Texas; 

 Las Vegas (6398 ft.) (W. M. Wheeler), Las Vegas Hot Springs (6726 

 ft.), and Romeroville (6303 ft.). New Mexico (T. D. A. Cockerell) ; 

 High Rolls (6550 ft.), Alamogordo (4320 ft.) and Beulah (8000 ft.), 

 New Mexico (H. Viereck). Two dealated females were taken at 

 Manitou and one at Ft. Davis. The workers from Colorado often 

 have the thorax rather pale, so that they approach very closely to 

 the var. occidentale Emery {vide infra), but I believe that this name 

 should be restricted to the Calif ornian form. 



Liometopum apiculatum Mayr var. occidentale Emery. 



Liometopum microcephalum Panzer var. occidentale Emery, Zool. Jahrb. Abth. 

 f. Syst., VIII, 1894, pp. 330, 331. $ , c5^. 

 Worker. — -Differs from the typical apiculatum in having the thorax and petiole 



