3 1 6 Bullletin American Museum of Natural History. [Vol. XXII 



22. Myrmica rubra lobicornis Nylandcr var. jessensis Forel. 

 FoREL, Ann. Soc. Ent. Belg., XLV, 1901, p. 371, $ 



According to Forel, the worker of this variety has "the antennal 

 lobe a little shorter than the type, the epinotal spines shorter and the 

 petiolar node more rounded, almost as in the var. schciicki Emery, 

 so that I cannot decide, notwithstanding the characters of the male, 

 to assign it to scabrinodis. It has the deep color of the lobicornis 

 of the northern Alps. Its antennal lobe is much more developed than 

 in the variety jracticornis Emery of the United States. " 



It is a significant fact that none of the forms of the circuinpolar 

 M. rubra are represented in Mr. Sauter's collections from southern 

 Japan. 



23. Leptothorax congruus F. Smith. 



F. Smith, Trans. Ent. Soc. London, 1874, p. 406, $ 



Worker. Length 2-2.5 nm^- 



Head, excluding the mandibles, longer than broad, with slightly convex 

 sides and straight posterior margin. Eyes a little in front of the middle. 

 Clypeus convex with nearly straight anterior border, without a median depression 

 or emargination. Antennse 12-jointed; tip of scape not reaching the posterior 

 comer of the head by a distance equal to its transverse diameter; first funicular 

 joint 3 times as long as broad, joints 2-8 distinctly broader than long, subequal, 

 joints 9-1 1 forming a club, the terminal joint of which is as long as the two 

 preceding subequal joints together. Thorax in front nearly two-thirds as broad 

 as the head, with rounded and sloping humeri, in profile straight above, with 

 barely indicated mesoepinotal constriction. Epinotal spines short, acute, about 

 a third the length of the straight basal surface, a little further apart at their 

 bases than long, directed outward, backward and a little upward. Petiole 

 from above nearly half as broad as the epinotum, more than twice as long as 

 broad, gradually widening anteriorly; in profile with a well developed node, 

 whose anterior slope is slightly concave and hardly longer than the convex 

 posterior slope. Postpetiole from above ij times as broad as the petiole, a 

 little broader than long, rectangular, in profile convex dorsally, especially in 

 front. Gaster flattened dorsoventrally, with straight anterior border. Legs 

 rather robust, femora incrassated in the middle. 



Mandibles coarsely striato-punctate. Clypeus longitudinally rugose, 

 smoother and more shining in the middle. Head, thorax and pedicel subopaque ; 

 head rather finely and longitudinally rugose-punctate; thorax irregularly and 

 coarsely rugose on the dorsal surface, pleurag and epinotum more finely and 

 reticulately rugose, as are also the petiole and postpetiole. Gaster smooth and 

 shining. 



Hairs white, obtuse, erect and rather short on the trunk; delicate, tapering 

 and appressed on the appendages. 



Dark brown; head and gaster nearly black; mandibles, legs and antennae 

 yellowish brown; antennal scapes and clubs, middle portions of femora and tibiae 

 darker and in some specimens almost black 



