172 
Psyche 
[Vol. 91 
The behavior of Cepha/otes atratus (Corn, 1980) and Zacryptoce- 
rus varians (Wilson, 1976; Cole, 1980) have been examined in detail. 
Both Wilson (1976) and Corn (1980) stressed the importance of 
studying the divergent genus Procrvptocerus in order to factor out 
behaviors that are related to ecological peculiarities from those tied 
to the evolution of polymorphism within the tribe. Among cephalo- 
tines, Procrvptocerus appears, at least superficially, most similar to 
typical myrmicine ants because the head and thorax lack elaborate 
spines and flanges. Further, since the worker caste is monomorphic, 
and therefore less complex than in other cephalotines, it has been 
assumed to be the most primitive genus of the tribe. 
The species P. scabriusculus is found from Mexico to Venezuela 
(Kempf, 1972). It nests in dead wood, principally twigs, and forms 
polydomous, polygynous colonies. Here I present the results of a 
behavioral study on workers and queens of P. scabriusculus as a 
contribution towards understanding the biology of this species and 
the relationship between behavior and polymorphism within the 
Cephalotini. 
METHODS 
Nests of P. scabriusculus were collected in Escazu, near San Jose, 
Costa Rica. Three clusters of inhabited twigs were taken in late 
August, 1 983, from Spondias purpurea . The colony observed in this 
study was extracted from 3 closely spaced dead twigs and presumed 
to be a major part of a single colony. It contained 6 queens, 62 
workers, 10 worker pupae, 1 male pupa, 49 larvae, and 27 eggs. 
Both trophic and normal eggs were present. One additional colony 
was collected in a fig tree in November, 1982. 
The observation nest was a 100 X 15 mm plastic petri dish. A 
small test tube, containing water held back by a cotton plug, was 
placed in the center of the dish to provide moisture and a nest site. 
The petri dish fit easily on the stage of a dissecting microscope. 
Observations used for the ethogram were made over a period of 7 
days. During this period, the colony was supplied with diluted 
honey and dead insects. The honey was quickly consumed by 
workers, but the insects were rarely touched. Occasionally, workers 
appeared to be drinking the body fluids of freshly killed insects. The 
colony was observed for a total of 20 hours, in 40 30-minute obser- 
vation periods. During each 30 minute period, the nest was scanned 
