48 
Psyche 
[March 
TWO MERMITHERGATES OF ECTATOMMA 
By William Morton Wheeler 1 
Since the publication in 1928 of my review of the modi- 
fications induced by Mermis parasites in various species 
of ants, two additional cases have been reported, one by 
Strelnikov (1928) in a Ponerine ant, Pachycondyla striata , 
from Paraguay, and one by myself (1929) in a Formicine 
ant, Camponotus (Tansemyrmex) punctatus from Argen- 
tina. Two other interesting mermithergates have just 
come to light among some ants collected by Mr. Nathan 
Banks and Mr. P. J. Darlington. One of these belongs to 
the typical Ectatomma tuberculatum Olivier, the other to 
its variety punctigerum Emery. As long ago as 1890, 
Emery (1890 a) mentioned a peculiar worker of the typi- 
cal E. tuberculatum , which we now know must have been 
a mermithergate, but he merely cites it as “analogous” to 
a similar specimen of Neoponera villosa with small head 
and voluminous abdomen. 
The mermithized specimen of the typical E. tuberculatum 
was taken by Mr. Banks on July 15, 1924, near the tropical 
laboratory on Barro Colorado Island, Panama. It measures 
nearly 16 mm. and is of the same brownish ferruginous 
color as normal workers from the same locality, but with 
the gaster distinctly darker. The head is smaller and nar- 
rower, with scarcely an indication of the posterior angles 
and with very slightly larger and more convex eyes. Ocelli 
lacking. Antennal scapes extending half their length be- 
yond the posterior corners of the head and the mandibles 
slightly narrower. Thorax shaped as in the normal worker 
but slightly less robust, with distinct, blunt teeth on the 
epinotum, Petiolar node more strongly compressed antero- 
posteriorly. Postpetiolar and gastric segments, especially 
"Contribution from the Entomological Laboratory of the Bussey 
Institution, Harvard University, No. 334. 
