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Psyche 
[Vol. 87 
the field only rarely, but they conclude, “In texture and general 
internal structure the nests and runways of N. ephratae are insep¬ 
arable from those of N. corniger". Based on a larger sample size, this 
paper presents evidence that colonies of the two species can be 
distinguished solely on the basis of nest architecture. 
This study is based on work done in Costa Rica and the Republic 
of Panama. Entire Nasutitermes nests of a variety of sizes were 
collected, measured, weighed, and completely dissected. Data pre¬ 
sented in this paper are based on 102 N. corniger colonies and 29 N. 
ephratae colonies collected in second-growth areas near Barro 
Colorado Island, Panama. Less quantitative but corroborating 
observations were made at La Selva, Sirena, and Llorona, Costa 
Rica and in a variety of places in central Panama. 
Both species of termite were identified by Dr. Kumar Krishna at 
the American Museum of Natural History, N.Y. In addition, 
specimens of N. corniger compare favorably with the syntype 
specimens (Museum of Comparative Zoology, Harvard University). 
Morphological differences between the two species are distinct 
among alates or reproductives, but subtle when comparing soldiers. 
N. corniger alates have black wings, dark bodies, and ocelli which 
are located relatively far from the eyes (by a distance of about twice 
the diameter of an ocellus) (Banks 1918, Dietz & Snyder 1923, 
Snyder 1959). N. ephratae alates have yellow-brown wings, brown 
bodies, and ocelli located close to the eyes (Banks 1918, Emerson 
1925, Snyder 1959, Mathews 1977). Soldiers are differentiated on 
the basis of head shape (Banks 1918) or amount of tergal pubes¬ 
cence (Snyder 1959), but these differences are not always prominent. 
In alcohol, N. ephratae soldier heads turn reddish-brown while 
heads of N. corniger soldiers remain a rich, dark brown (pers. obs.). 
Voucher specimens from this study have been deposited at the 
Museum of Comparative Zoology (N. corniger nest numbers 3, 4, 
23, 46, 80; N. ephratae nest numbers 22, 28, 31, 92). 
Differences in External and Internal Architecture 
The dark brown surface of an N. corniger nest is coarse with small 
bumps covering the entire exterior [Figure la]. Nests tend to be 
roughly spherical when small (diameter C20 cm), and grow more 
ellipsoidal as they enlarge. (The largest N. corniger nest dissected in 
this study was 68 X 46 X 34 cm 3 ; 28.0 kilos.) Localized additions to 
