416s. Bulletin American Museum of Natural History. [Vol. XXXIV, 
Described from a long series of workers which I found nesting in small 
craters 3-4 inches in diameter in the deserts around Tucson, Arizona (type 
locality) and five workers from Phoenix in the same state. 
44, Xiphomyrmex spinosus wheeleri Forel. 
Forel described this ant as a distinct species from specimens which I 
took.many years ago in the dry desert at Pacheco, in Zacatecas, Mexico, 
but a study of three cotypes in my collection shows that it can hardly be 
more than a subspecies of spinosus. As stated by Forel, it differs from 
spinosus in having a distinct mesoépinotal constriction, in the shape of the 
metasternal angles which are small and blunt, in the stouter epinotal spines 
and in having the first gastric segment, except for the scattered piligerous 
punctures, smooth and shining. The hairs on the legs are oblique, those on 
the body are pointed, of unequal length, but on the whole decidedly longer 
than m the preceding subspecies. The clubs of the antennal scapes are 
infuscated. The head is not more deeply excavated behind than in hirsutus, 
but the upper surface of the petiole is coarsely longitudinally rugose. 
JI refer two workers which I took in Miller Cafion, Huachuca Mts., 
Arizona, to this subspecies though their epinotal spines are distinctly smaller 
and the rugosity of the postpetiole is more irregular than in the Mexican 
cotypes. The antennal clubs are not infuscated. The Arizona specimens 
may represent a distinct variety but the material is hardly sufficient to 
justify the introduction of a new name. 
45. Xiphomyrmex spinosus insons subsp. nov. 
Worker. Length: 3.5-4 mm. 
Very similar to the subspecies wheeleri, with the epinotal spines long and slightly 
curved at their tips, the metasternal angles produced into sharp, compressed spines: 
nearly half as long as the epinotal spines, with acute, upturned tips. The post- 
petiole is twice as broad as long and about 3 as broad again as the petiole, its upper: 
surface coarsely and regularly longitudinally rugose, the gaster smooth and shining, 
with small, scattered, piligerous punctures. Head very distinctly excised behind; 
thorax without mesoépinotal constriction or impression. Erect hairs on the body 
long and abundant, of unequal length and pointed as in wheeleri, those on the legs. 
reclinate. Some specimens show a slight infuscation of the antennal clubs. 
Female. Length: 4~4.5 mm. 
Closely resembling the worker; pronotum and epinotal declivity transversely, 
mesonotum, scutellum and pleure coarsely, longitudinally rugose. Wings yellowish. 
hyaline, with pale brown veins and darker brown stigma. 
Male. Length: 3.5-4 mm. 
