1903.] NATURAL SCIENCES OF PHILADELPHIA. 241 



which had been eaten off b}' cattle and hollowed out, perhaps by some 

 larger insect than Leptothorax. At all events, when I visited these 

 colonies in autumn (I knew of their existence by watching foraging 

 workers going in and out of the nests) every colony had been dislodged 

 and dispossessed of its premises by a species of wasp which was busily 

 bringing in paralyzed spiders. The L. curvispinosus had then retired 

 to hollows in stumps or logs or dead branches lying on the ground." 

 This species is also of interest because it is enslaved by Tomognathus 

 americanus Emery, in the nests of which it has l^een found b}^ Per- 

 gande. 



9a. Subsp. ambiguus Emery (I'l. XII, fig. U). 



L. curvispinosus Mavr subsp. ambiguus Emory, Zool. Jahrb. Abth. f. Syst., 

 VIII, 1894, p. 320^. 



Differs from the t3'pical curvispinosus in the somewhat coarser sculp- 

 turing and the decidedly shorter and nearly straight epinotal spines. 



Type locahties: Hillbity, S. Dak. (Pergande) ; Cleveland, O. (Was- 

 mann); New York (Schmelter). 



A number of specimens collected at Colebrook, Conn., have the same 

 sculpturing as the typical curvispinosus but decidedly shorter epinotal 

 spines. These were found running on the surfaces of leaves in the 

 shade of very damp woods. I failed to discover the nests. 



9b. Subsp. rugatulus Emery (PI. XII, fig. 12). 



L. rugatulus Emery, Zool. Jahrb. Abth. f. Syst., YIII, 1894, p. 321. 

 Owing to the existence of the next subspecies (anncctcns) , I feel justi- 

 fied in regarding Emery's L. rugatulus merely as a subspecies of 

 curvispinosus. The type specimens were from South Dakota (Per- 

 gande) and Colorado (Pergande). Specimens from Seattle, Wash. 

 (Kincaid), in my collection agree very closely with Emery's description. 

 They differ from the typical curvispinosus in the following characters : 

 The rugse of the head and thorax are decidedly coarser, and longitudi- 

 nal on the latter. Epinotal spines much shorter and hardly curved. 

 Tooth on the anterior ventral surface of the petiole distinctly larger, 

 blunter and directed downward and forward. Postpetiole broader 

 than long, oblong when seen from above, with rather distinct anterior 

 angles. In profile the upper surface of the postpetiole is almost angu- 

 lar, its ventral surface very short. Upper surface of head and gaster, 

 with the exception of the posterior edges of the segments of thejatter, 

 dark-brown. Femora more or less infuscated in some specimens. 



9c. Var. Cockerelli var. nov. 



Worker. — Length 2-2.5 mm. 



Differs from the typical rugatulus in having the head, thorax~and 

 16 



