1932 ] 
Female of Acamatus from Texas 
73 
A NEW FEMALE OF ACAMATUS FROM TEXAS 
By William S. Creighton 
Department of Biology, College of the City of New York 
It has now been almost half a century since Ernest Andre 
gave us the first description of one of the peculiar apterous 
females of the New World legionary ants. Contrary to 
custom the recognition of this caste added further com- 
plexity to an already difficult problem since it showed that 
the female Eciton as well as the male cannot be correlated 
with the worker caste by the usual structural criteria. For- 
tunately the female is not likely to be taken alone but the 
extreme rarity of this caste and the difficulties attendant 
upon the capture of some of these insects have greatly 
impeded our knowledge of the sexual forms of Eciton. The 
activities of a number of investigators, not infrequently 
undertaken at considerable personal risk, have resulted in 
the discovery of females belonging to about a dozen species. 
There remain, however, almost three times this number of 
species known only from the worker caste and a large num- 
ber of described but uncorrelated males. Under such cir- 
cumstances it is very gratifying to have the privilege of 
describing another female of these curious insects. 
Through the courtesy of Dr. Herbert Ruckes of the De- 
partment of Biology of the College of the City of New 
York, the author was given a colony of Acamatus taken by 
Dr. Ruckes near Ft. Worth, Texas. This colony contained 
numerous workers and a single female. I wish to thank 
Dr. Ruckes for his generosity and to congratulate him upon 
his good fortune in finding one of these rare insects. 
A comparison of the workers from the above colony with 
material in my collection indicated that they belonged to 
Emery’s species wheeleri. In order to make certain of this 
determination specimens were sent to Dr. W. M. Wheeler 
for comparison with type material. Dr. Wheeler, who very 
