1903] WHEELER: — STEXAM.MA SEXSU STRICTO 1 67 



than in hrevicorfie typ. and in profile angular above. Mesoepinotal 

 depression very marked. Virginia (Forel, Pergande) ; Beatty, Pa. (Schmitt ) . 



subsp. impar Forel. 



2. Sculpture and color as in /V;//^?r. Length 2.5-3 mm. Eye very small, 



with not more than three or four ommatidia in its greatest diameter. 



Mesoepinotal depression shallower than in the preceding forms. Epinotal 



spines small. Petiolar node longer, lower and more rounded than in 



impar. St. Vincent, Pa. (Schmitt). . subsp. schmittii, subsp. nov. 



II. Back of head, thorax and nodes of pedicel more or less shining, when seen 



under a low magnification, on account of the coarser rugosity and smoother inter- 



rugal spaces ; sculpture of the pro- and mesonotum sharp and regular, the rugae 



straight in the middle and curving on the sides. 



1. Length 2.75-3. •'i'"'"- Color usually reddish brown. Mesoepinotal 

 depression moderate. Epinotal spines robust, only slightly directed 

 upwards. Yale, B. C. (Emery); Beatty, Pa. (Schmitt); Colebrook, Conn. 

 (Wheeler); Rockford, 111. (Wheeler); Pacific Grove, Cal. (H. Heath). 



subsp. diecki Emery. 



2. Somewhat larger and darker brown, mesoepinotal depression broad 

 and deep. Epinotal spines very short, blunt and directed more upwards 

 than in diecki. Head less shining behind and thoracic rugae coarser and 

 less numerous. Rich Springs, N. Y. (Emery) ; Vermont (Forel) 



var. impiessuni Emery. 



A fine colony of the typical hrcviconie, comprising all three phases was sent 

 me by Mr. C. E. Brown, who found it under a stone at North Milwaukee, Wis.^ 

 May nth, igoi. At Rockford, 111., I have taken several colonies of this form, 

 rarely under stones, but most frequently under the thick layer of dead leaves and 

 vegetable mould which accumulates in rich, damp woods. In this locality I did 

 not see the winged sexes till July 25th-Aug. 19th. The early capture of these 

 by Mr. Brown would seem to indicate that they sometimes pass the winter in a 

 virgin state in the parental nest. 



The colonies are always very small, comprising not more than 20-60 workers 

 and very often even less. They resemble colonies of Leptothorax, especially 

 when they are found, as is sometimes the case, nesting in hollow acorns embedded 

 in the vegetable mould. The species is very timid, and apparently either nocturnal 

 or subterranean in its habits. This seems to be indicated by the coloration, the 

 small size of the eyes in the workers, and by the fact that I have never seen these 

 insects moving about on the surface of the ground even on dark, cloudy days. 

 They probably feed on small larvae and other animal food. ^. brevicorne, like 

 S. nea/'ctiium, is a sub-boreal form and has not been found up to the present time in 



