164 
Psyche 
[September 
Mandibles composed of a short basal portion from which project 
three long spines. Outermost spine evenly curved and tapering 
towards its tip which just reaches the opposite side of the head 
when the mandibles are retracted Median spine less curved 
and about two thirds as long as the outermost. Innermost 
spine straight, one third as long as the outermost. Clypeus 
slightly concave. Prothorax, seen from above, with strongly 
convex sides, considerably broader than the remainder of the 
thorax and separated from it by an impressed suture; in profile 
Fig. 1. Thaumatomyr mex cochlearis sp. nov. worker. A , dorsal view of head ; B, profile 
view. 
subquadrate, slightly convex above. Mesonotum greatly re- 
duced, barely one tenth as long as the pronotum. Epinotum 
about one and one half times as long as the pronotum, its basal 
face, in profile, feebly convex, much longer than the declivious 
face from which it is separated by a well marked angle. Petiole, 
seen from above, trapezoidal, widest behind, slightly wider than 
the epinotum; in profile slightly higher than the epinotum, the 
summit convex, passing by a curve to the somewhat slanting 
anterior face and more abruptly to the almost perpendicular 
