544 WHEELER. 



138. Formica whymperi Forel. 



This form, as above stated, was described by Forel as a mere variety 

 of F. rvfa obsciiripes. During August 1915 I found several colonies 

 of it on the shores of Emerald Lake in British Columbia. It evidently 

 belongs to the microgyria group and is specifically' the same as my F. 

 adamsi described from Isle Royale, Mich. The colonies are rather 

 small and nest under stones and logs which they bank with accumu- 

 lations of vegetable detritus. The worker of the form which I take 

 to be the same as the type is larger than adamsi, measuring 3.5-6 mm. 

 The petiole is blunter and thicker and is produced upward in a blimt 

 point, the hairs on the head and thorax are somewhat less numerous, 

 the dark portion of the gaster is black and not dark brown as in adamsi 

 and the black markings of the head and thorax are more pronounced 

 and more sharply outlined in the large workers. F. adamsi is, there- 

 fore, to be retained as a variety of whymperi. 



139. Formica ichymperi var. alpina Wheeler. 



This variety must also be referred to whymperi. I have recorded 

 it from Pikes Peak, 10500-11000 ft., (type locality), Troy, Idaho and 

 Cape Breton Island, but further examination leads me to doubt 

 whether the specimens from the two latter localities really belong to 

 this form. I am not even certain that ivhymperi and microgyna are 

 specifically distinct. Both of these forms, with their subspecies and 

 varieties constitute a very difficult complex which can be satisfactorily 

 analyzed only with the aid of more material and with a better knowl- 

 edge of the males and females than we possess at present. 



140. Formica nevadensis Wheeler. 



Known only from a single female taken in Ormsby County, Nevada 

 by Prof. C. F. Baker. As this county is on the eastern shore of Lake 

 Tahoe we might expect the specimen to be the female of one of the 

 three Californian forms of microgyna described above, but this cannot 

 be the case owing to the peculiar abundant pilosity on the body and 

 antennal scapes of the Nevada specimen and the very smooth and 

 shining gaster. 



141. Formica exsectoides Forel var. hesperia Wheeler. 

 Known only from the vicinity of Colorado Springs. 



142. Formica exsectoides subsp. opacive7itris Emery. 

 Colorado: Creede, 8844 ft. (S. J. Hunter). 

 Wyoming: Yellowstone National Park (J. C. Bradley). 



