268 Bulletin American Museum of Natural History. [Vol. XXI, 



Colo., by the late P. J. Schmitt, O. S. B.; at Broadmoor and Roswell 

 near Colorado Springs, Colo., by myself, and at Glorieta and Old 

 Pecos Pueblo, New Mexico, by Professor T. D. A. Cockerell. This 

 seems to be the form designated by Professor Emery as a variety of 

 F. pergandei from Colorado (Zool. Jahrb. Abth. f. Syst. VII, 1893, 

 p. 647). It is closely allied to this species but may be readily dis- 

 tinguished by the dense gray pubescence and obtuse white hairs on 

 the gaster of the worker, and the less elongated head and more convex 

 cheeks, especially in larger specimens. According to Emery's de- 

 scription of pergandei, it would differ also in having erect hairs on the 

 lower surface of the head, but two cotypes of Emery's species in my 

 collection — one received from Professor Emery and the other from 

 Mr. Pergande — each have a few such hairs. 



While collecting in the vicinity of Colorado Springs, during the 

 summer of 1903, I found many colonies of F. niunda. They were al- 

 ways in grassy places and most abundant in the irrigated plains about 

 Broadmoor and in the pastures near the racing stables at Roswell. 

 The species did not occur in the higher mountainous regions about 

 Cheyenne Canon and Manitou. The colonies were rather small, com- 

 prising only a few hundred workers, and made rather obscure mound- 

 nests much like those of F. schaufussi and its varieties. I never 

 found these colonies nesting under stones and in no case did they con- 

 tain slaves, although a single colony of the allied pergandei, found in 

 the very same locality (Broadmoor), contained workers of F. subpolita. 

 It would seem, therefore, that although F. niunda has a notched 

 clypeus, it does not have the dulotic instincts of the allied F. pergandei 

 and sanguinea. 



2. Formica dryas sp. nov. 



Worker. — Length, 5-7 mm. 



With the habitus of F. rtija. Mandibles 8-toothed. Head, excluding man- 

 dibles, as broad as long, posterior border straight, sides rather flat, converging 

 anteriorly. Clypeus sharply carinate, not produced in front, with nearly 

 straight anterior border. Thorax rather robust, epinotal declivity much flat- 

 tened, distinctly longer than the slightly convex basal surface. Petiole some- 

 what convex in front and very flat behind, with sharp superior border; seen 

 from behind it is broad above in large workers and much produced in the 

 middle, with straight sides rapidly converging below. Gaster and legs of the 

 usual shape. 



Head, thorax, petiole and appendages subopaque, finely but distinctly 

 shagreened. Mandibles densely striatopunctate ; clypeus and especially the 

 frontal area smooth and shining. Gaster shining, very finely and transversely 

 shagreened, with the appearance of "watered" silk. 



Body clothed with short, erect or suberect, subobtuse, yellowish hairs, 



