76 
Psyche 
[June 
of many ant species that have been collected on Barro Colorado a 
single time, despite the very intensive collecting of its whole area by 
several ant specialists, as well as the long-time Resident Naturalist, 
James Zetek. It has been said that Barro Colorado is so well collected 
for ants that scarcely anything in the way of new species can be collect- 
ed there. That McCluskey and I, engaged in what was primarily an 
ecological survey not particularly directed toward the finding of 
novelties, were able to find this Amblyopone and at least two other 
undescribed ant species in the square mile centered on the Laboratory 
Clearing, speaks for the virtual inexhaustability of the island’s ant 
fauna and for the richness of tropical forest faunas in general. 
In the key to the New World Amblyopone in my i960 review (p. 
191 to 192) , A. tropicalis runs to couplet 8, where its intermediate size 
makes it fall ambiguously into either 8 or 9. Of the three species in 
these two couplets \orizabana Brown, bierigi (Santschi), chilensis 
Mayr], A. tropicalis is closest to orizabana in structure and to chilen- 
sis in size, but differs from these in the reduced number of teeth in 
the clypeal armament, in the strongly projecting, large median fusion 
tooth, and in the nearly obsolete dorsal members of the mandibular 
double teeth, rendering the tooth row apparently single as seen from 
dorsal view. A. tropicalis is larger than orizabana , has relatively long- 
er and more slender mandibles and a broader head. 
