Thaumatomyrmex

The five species of Thaumatomyrmex may be separated bymeans of the following key:

1. Apical teeth of closed mandibles not exceeding lateral margins of head...... 2

Apical teeth of closed mandibles exceeding lateral margins of head.......... 3

2. A basal fourth tooth on mandible lacking. Cuba........ cochlearis Creighton

A basal fourth tooth on mandible present. Brazil............ mutilatus Mayr

3. Lateral margins of head strongly diverging anteriorly. Bolivia. .. manni Weber

Lateral margins of head moderately divergent........................... 4

4. Third tooth, when mandibles closed, barely reaching mid-line of head. Honduras................................................. ferox Mann

Third tooth, when mandibles closed, distinctly exceeding mid-line of head. British Guiana and Trinidad................................ atrox Weber