242 PROCEEDINGS OF THE ACADEMY OF [Fcb,. 



patiole less opaque, owing to the rugiB being further apart and the 

 smooth interrugal spaces more prominent. Epinotal spines shorter 

 and more acute. Postpetiole somewhat longer, being intermediate in 

 shape between that of the typical curvispinosus and rugatulus, but 

 distinctly wider in front than behind, and with rounded but percep- 

 tible anterior angles. The coloration is also intermediate between the 

 forms just mentioned. Upper surface of head pale-brown and more 

 of the cheeks, sides and front of head yellow than in rugatulus, whereas 

 the infuscation of the gaster is limited to the posterior dorsal half or 

 two-thirds of the first segment, leaving the remaining segments yellow. 



Female (dealated). — Length 3-3.5 mm. 



Whole body, with the exception of the legs and antennae, yello\^^sh- 

 brown; head and gaster, with the exception of the base of its first 

 segment, darker. Antennae and legs more yellowish. Pedicel, espe- 

 cially the petiole, very rough, and surmounted by a more acute node 

 than in the worker. 



A fine living colony of this species, comprising more than a hundred 

 workers and eight females, was sent me by Prof. T. D. A. Cockerell 

 from Las Vegas Hot Springs, N. ^I. Fragments of bark accompany- 

 ing the ants showed that the nest was found in a tree trunk. 

 9d. Subsp. annectens subsp. nov. (PI. XII, fig. 13). 



Worker. — Length 2-2.5 mm. 



This form has the epinotal spines long and thin, and shaped like those 

 of the typical eurvispiiiosus. Head very coarsely longitudinally rugose, 

 subopaque. Pronotum evenly and coarsely foveolate-punctate, meso- 

 and epinotum opaque, coarsely reticulate rugose, the rugae without a 

 longitudinal trend. Petiole and postpetiole opaque, shaped like those 

 of rugatulus, the former with a prominent ventral tooth, directed down- 

 ward and forward. Upper surface of head and whole dorsal surface of 

 gaster, except a large, transversely elliptical spot on the anterior 

 portion of the first segment and the extreme posterior edge of this and 

 the remaining segments, dark-ljrown or black. Remainder of body 

 brownish-yellow. 



Type locality : Boulder, Colo. 



Described from four specimens collected by Rev. P. J. Schmitt, 

 O.S.B. 



This form is clearly intermediate in structure and coloration be- 

 tween the typical curvispinosus and the subspecies rugatulus. 

 10. Leptothorax Schmittii sp- uov. 



Worker (PL XH, fig. 14).— Length 2-2.25 mm. 



Head conspicuously narrow, with parallel sides, decidedly longer 



