72 
BiiUetin Wisconsin Natural History Society. [Vol. 5, No. 2. 
are more pointed, and the thorax is more robust than in the male of 
the typical form. The pronotum and scutellum are much more opaque 
and heavily sculptured, the former being densely punctate and rugose, 
with three shining streaks, one down the middle and the others over 
the parapsidal furrows. The scutellum and epinotum are densely 
reticulate-punctate. In the typical emersoni the pronotum is shining, 
distinctly foveolate in front and rugose-punctate behind. The wings 
of. glaciaUs are larger, broader and more whitish. 
L. emersoni and its subspecies belong to a small group of the 
genus characterized by ii-jointed antennae in the worker and 
female and a distinct though feeble constriction of the thorax at 
the mesoepinotal suture. For this group, which com- 
prises also the circumpolar L. acervomm, muscorum and 
hirticornis, and the neoboreal provancheri, Ruszsky'^ has 
recently erected a distinct subgenus, Mychothorax. L. emersoni, 
is evidently very closely related to L. provancheri Bmery, 
but the latter is said to have clavate hairs on the tibiae, whereas in 
the former the hairs both on the body and tibiae, though often 
obtuse, are never clavate. As Emery described provancheri from 
a single specimen, this species, when more specimens are avail- 
able, may prove to be cospecific with the one I have called 
emersoni. 
Examination of several hundred specimens from a large num- 
ber of colonies of Myrmica rubra from different parts of North 
America convinces me that Emery t was right in concluding that 
the trtie palearctic M. rubra sulcinodis Nyl. does not occur in this 
country, but is replaced by a distinct subspecies, brevinodis. . Of 
this Emery distinguished two forms, the typical brevinodis and a 
variety which he called sidcinodoides, because it approaches the 
European subspecies somewhat more closely. More recently Forel 
*The Ants of the Russian Empire. Kasan, 1905, p. 609 et seq. (in 
Russian) . 
fBeitrage zur Kenntniss der nordamerikanischen Ameisenfauna. 
Zool. Jahrb. Abth. f. Syst. VIII, 1894, pp. 312, 313. 
J Descriptions of Some Ants from the Rocky Mountains of Canada. 
Trans. Ent. Soc. Lond. 1902, pp. 699, 700. 
