1905.] Wheeler, Ants of the Genus Liometopum. 3^5 



of a clearer and more yellowish red color, although in many specimens the pro- and 

 mesonotum are spotted with black or fuscous. In some individuals the node of 

 the petiole when seen from behind is somewhat rounder and more like that of the 

 European ■microcephalum. On the antennal scapes there are erect hairs, which 

 are lacking in all my specimens of the typical apicidatiim. This character will 

 serve to distinguish occidcntale from the similarly colored workers of apicidatutn 

 often seen in Colorado. 



The types are from San Jacinto (1533 ft.) and Mariposa (1962 ft.), 

 California (Collection of Professor Emery at Bologna). 



My specimens were taken near Baldy Peak, San Gabriel Mountains, 

 California (6500 ft.), by Messrs. Brewster, Joos, and Crawford, and 

 near Claremont, California (1141 ft.), by Professor C. F. Baker. 



Liometopum apiculatum luctuosum subsp. nov. 



Worker. — Length 2.5-4.5 mm. 



Apart from its somewhat smaller size, the worker of this subspecies differs 

 from the typical apiculatum in sculpture, pilosity , and color. The body is much 

 smoother and more shining. The pubescence is shorter even on the gaster so 

 that the smooth surface is more apparent, and there are only a few rather short, 

 erect hairs on the upper surface of the body and none on the legs or antennal 

 scapes. All the specimens are black or very dark brown, with the mandibles, 

 lateral corners of the clypeus, the mouth, and in some specimens also the funiculi 

 or even the scapes of the antennas dark red or yellowish red. Insertions of 

 antennae and articulations of legs yellowish. 



The types of this well-marked form are from Cheyenne Canon 

 (7000 ft.) near Colorado Springs, Colorado. I have also taken it at 

 Prescott, Arizona (5320 ft.), in the Coconino forest on the rim of the 

 Grand Cafion of the Colorado (6865-7050 ft.), and down the Bright 

 Angel Trail to an altitude of about 4000 feet. A number of workers 

 were also collected by Messrs. Brewster, Joos, and Crawford near 

 Baldy Peak in the San Gabriel Mountains, California (6500 ft.). 



The Habits op Liometopum. 



L. apiculatum is structurally so closely related to the European 

 microcephalum that we should expect to find a similar close resem- 

 blance in habits. Generally speaking, this proves to be the case. 

 There are, however, a number of rather important ethological differ- 

 ences, which leave no doubt that the American is sufficiently distinct 

 from the European form to be regarded as a "good" species. 



The habits of L. microcephalum, which seems to be common in 

 Asia Minor and southern Europe (excepting France and Spain i), 



' According to Er. Andr6, Species des Hym^nopt^res d'Europe et d'Algerie, 1882, p. 220. 



