1907.] Wheeler, Fimgvs-gr owing Ants of North America. 797 



have many peculiarities of behavior similar to those of the smaller Attii 

 is shown by Santschi's observations on Oxijopomyrmex santschii Forel of 

 the Tunisian deserts. In a letter to Forel, Santschi states that the nests of 

 this ant are "so characteristic that when one has once seen one of them, 

 nothing is easier than to find others. I am surprised to find that they have 

 not attracted the attention of other observers. Especially remarkable is 

 the tiny crater, wliich has the form of a cone, hardly more than 4-5 cm. in 

 diameter and 2. .5-3 cm. high. The circumference of its funnel-shaped top 

 is 3-4 cm. across and its margin is always perfectly circular and entire, ex- 

 cept in nests in process of construction, where it is at first semilunar like the 

 very small nests of Messor arcnarius. At the bottom of the funnel the small 

 entrance is found, 1-2 mm. in diameter, just large enough to permit one of 

 the workers to pass. A single nest has rarely two entrances and two cones. 

 A single perpendicular gallery descends below the surface. A first chamber 

 is found at a depth of 2-3 cm. It is horizontal, attaining a length of o cm., 

 a breadth of 1 cm. and a height of 5 cm. In this first chamber the pupae 

 are kept for the purpose of enjoying the warmth and here I have found a 

 number of workers and winged females. Thence the gallery continues to 

 descend to a depth of 15-20 cm. and finally opens into two or three chambers 

 of the same dimensions as the first. These contain pupte and an ample 

 provision of very small seeds. This ant is therefore granivorous. I sur- 

 prised a few of the workers entering the nest with seeds in their mandibles. 

 They go out foraging singly and not in files like Messor and other genera. 

 They are very slow in their movements and are very apt to stop motion- 

 less at the least alarm. Day or night one or tvs'o of the workers may be 

 seen on the outer surface of the crater scarcely moving unless molested, but 

 when disturbed they hurriedly retreat into the nest to spread the alarm. 

 Their habits are rather nocturnal. If a light is brought near the nest when 

 a worker is on the point of leaving it with a grain of sand she hurriedly backs 

 into the entrance and there stops, closing it perfectly with her ))urden. 

 If the observer remains very quiet, she eventually comes forth and deposits 

 her load on the slope of the crater. There are scarcely more than thirty 

 individuals in a nest." 



Although Oxyopomipmex has no close taxonomic relations with the Attii 

 or Tetramorii, but rather with members of the complex genus Stcnamma, 

 it closely resembles Trachijmyrmex turrifex and Mijceto.sorifis harfniaiini 

 in the small size of its colonies, the slowness of its movements and the .struc- 

 ture of its nests. These resemblances are in all probaljillty. due to conver- 

 gent development. Xevertheless, species with luil)its like Oxi/opomi/rnicx 

 might conceivably become fungicolous by some such substitution of instincts 

 as that suggested by von Ihering. .So many assumptions, however, would 



