64 Bulletin American Museum of Natural History. [Vol. XXII, 



onies. They measured only 3-3.5 mm. while the largest workers were 

 5.5-6 mm. in length. The nest was discovered too late in the season 

 to contain males and females. Both this and the Mt. Vernon colonies 

 were located on the sunny border of some open woods where the typ- 

 ical schatifussi and its var. incerta are unusually abundant. There can 

 be little doubt that one or the other of these ants functions as the tem- 

 porary host of difficilis. This species occurs also near Halifax in the 

 Ramapo Mountains of northern New Jersey, where I captured a few 

 workers attending aphides on trees at an altitude of about 800 feet. 

 Mr. Wm. T. Davis has brought me several specimens taken at Inwood, 

 N. Y., a locality in which the last traces of the original ant-fauna of 

 Manhattan still linger at the northernmost end of the island. 

 3. Formica nepticula Wheeler. 

 This species, which I have described in a recent paper, ^ is of unusual 

 interest because it has females even smaller than those of F. difflcilis; 

 quite as diminutive, in fact, as those of F. microgyna and nevadensis. 

 A single colony of nepticula was located during August, 1904, at Cole- 

 brook, Conn. , but as at that time it appeared to contain only workers 

 it was regarded as a colony of F. dryas or of some form of rufa. June 

 30 of the current year when I again visited the nest, which was under a 

 large stone banked with vegetable debris like the nests of F. consocians, 

 I was surprised to find several diminutive, mostly callow females 

 and a considerable number of cocoons all of about the same size. 

 A large part of the colony was transferred to an artificial nest. During 

 the first week in July many of the little females but only two males 

 made their appearance. The workers of the season did not begin to 

 hatch in numbers till July 9 to 21. The date of the nuptial flight is 

 approximately July 11. 



The small size of the females indicates that this species, like con- 

 socians, microgyna, montigena, etc., is a temporary parasite on some 

 other species of Formica of the fusca or pallide-fulva groups, but 

 we can only conjecture which of the species nesting in the same 

 locality is used for this purpose. These species are: F. subsericea, 

 neogagates, incerta, nitidiventris , and the typical schaufussi. The 

 coloring of the nepticula female is remarkably like that of certain 

 workers of three of these forms, namely: neogagates, incerta, and nit- 

 idiventris. The only colony of nitidiventris I found during the summer 

 was used for experiments with consocians. The results of my attempts 

 to get the other species of Formica to adopt nepticula females are here 

 given in condensed form: 



1 New Species of Formica. Bull. Amer. Mus. Nat. Hist., Vol. XXI, 1905. p. 270. 



