The Ants of the Baltic Araber. 



55 



AphfBu Of/aster tnersa, sp. nov. 

 Worker (Fig. 20). Length about 5,5 mm. 



Differing from A. sommerfeldti in the following characters: The 

 anterior border of the mesonotum does not project above the pronotum 

 and the epinotal teeth are broader 



and blunter. The head and tho- .^^^qj 



rax and perhaps also the petiole 

 and postpetiole are very coarsely 

 reticulate rugose, and not longi- 

 tudinally rugose, except on the 

 front of the head. 



This species is based on a 

 single specimen (B 18 509) in the 

 Geolog. Inst. Koenigsberg Coll. 

 This specimen, though in a small 

 piece of amber, is not very clearly 

 visible, owing to a thick white 

 film which envelops the whole 



left side of the body and the whole gaster, and a crack which ob- 

 scures the anterior portion of the head. 



Fig. 20. Aphaenogaster mersa, ep. nov. 

 Worker, B 18509. 



Grenus Electroniyrtnex, gen. nov. 



Worker. Body slender. Head rather large, longer than broad, 

 narrowed and depressed behind, with prominent occipital margin and 

 large, convex eyes, situated in front of the middle and very near the 

 anterior border, so that the cheeks are extremely short. Ocelli absent. 

 Clypeus very short, extending back between the short and indistinct 

 frontal carinae. Frontal area obsolete. Mandibles very long, narrow, 

 sublinear, with concave external border near the base and with 

 distinct masticatory and basal borders the former straight and 

 minutely and uniformly denticulate throughout its length. Antennae 

 slender, 12-jointed, with all the funicular joints longer than broad, 

 the terminal ones not forming a distinct club. Thorax narrower than 

 the head, prothorax greatly elongated, especially in front, where it 

 tapers to form a slender neck, not distinctly marked off from the 

 humeri, Mesonotum short and narrow; mesoepinotal constriction 

 distinct. Epinotum nearly as long as the pronotum but higher, with 

 the base convex and longer than the concave declivity, and armed 

 with two small, erect spines. Petiole slender, cylindrical, with only 

 a faint indication of a node above, not dentate beneath. Postpetiole 



