The Ants of tke Baltic Amber. 
55 
Aphcenogaster mersa , sp. nov. 
Worker (Fi g. 20). Length about 5,5 mm. 
Differiug 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- 
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 Coli. 
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. 
Genus JElectromyrmex 9 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 carinm. 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 
Fig. 20. Aphaenogaster mersa, sp. nov. 
Worker, B 18509. 
