66 
William Morton Wheeler 
but little broader than the petiole and slightly broader than long. 
Gaster elliptical, its basal border not straight and transverse. Legs 
rather slender. 
Head, thorax, petiole and postpetiole densely punctate, and the 
head and thorax also coarsely reticulate-rugose. 
Erect hairs on body long, thick, blunt and clavate, much more 
conspicuous than in any of the other amber species of Leptothorax ; 
hairs on the scapes and legs short, appressed and pointed. 
Color red, surface more or less enveloped in a golden air film. 
Described from a single specimen (X B 1270) in the Geolog. 
Inst. Koenigsberg Coli. This species is easily recognized by its peculiar 
sculpture, long, stout epinotal spines and coarse, clavate hairs. 
Leptothorax placivus, sp. nov. 
Work er. Length about 3,5 mm. 
Head and eyes rather large. Antennae 11-jointed; first funicular 
joint as long as the two succeeding joints together; joints 2 — 9 
distinctly longer than broad ; terminal joint of club as long as the two 
preceding joints together. Thorax rather robust, with very distinct 
mesoepinotal constriction, on both the dorsal and pleural surfaces. 
Epinotum with two very blunt teeth or angles instead of spines, the 
base convex and a little longer than the concave, sloping declivity. 
Petiole about l 1 /^ times as long as broad, its node rather sharply 
angular in profile, with straight anterior and posterior slopes; its 
border straight and transverse. Postpetiole broader than long, broader 
than the petiole, very convex and rounded above. Gaster somewhat 
flattened above, convex below. Femora and tibiae incrassated. 
Mandibles striatopunctate ; head finely reticulate and smooth, 
except the cheeks, which are coarsely longitudinally reticulate-rugose 
and the clypeus, which is finely and longitudinally rugulose. Thorax 
coarsely punctate, the pleurae and epinotum also coarsely longitudinally 
rugose, the pronotum with feebler and more numerous rugae. Petiole 
and postpetiole finely rugulose-punctate. Gaster and legs smooth and 
shining, with small, scattered, piligerous punctures. 
Hairs very sparse, distinct only on the petiole, postpetiole and 
gaster, where they are moderately long and blunt, on the petiole and 
postpetiole also slightly clavate; on the scapes and legs the hairs are 
very fine and appressed. 
Color blackish, legs and antennae red in transmitted light. 
Described from a single, beautifully preserved specimen (without 
a number) in the Geolog. Inst. Koenigsberg Coli. This species is easily 
