* 
572 THE AMERICAN NATURALIST. [Vor. XXXIV. 
long, which is so much like a small worker, Eczton sumichrastt, 
that I did not notice it in the artificial nest till the ants had 
been under my observation for a month! One morning I 
happened to see it as it was marching around the nest in the 
files of the Ecitons. The movements of its legs and anten- 
nz were precisely like that of its hosts. This resemblance 
extends also to its size, coloration, and the character of the 
surface of its body. Its head, thorax, and elytra are opaque, 
dark red, rather irregularly punctate, and furnished with a few 
scattered hairs. The abdomen is smooth and shining, of a 
lighter red color, widened towards the tip, and covered with 
longer, denser hairs than the remainder of the body. The 
eyes are well developed. The antennz show a decided resem- 
blance to those of the ant. The most striking character, 
however, is a very deep, elongate elliptical depression in the 
middle of the pronotum. The bottom of this depression 
seems to be formed by a white membrane. It is difficult to 
assign a function to this singular structure, unless it be the 
orifice of a huge gland that may secrete some substance 
relished by the Ecitons. During life the broadened tip of the 
shining red abdomen is bent up after the manner of staphy- 
linids, and the resemblance of the insect to a worker Eciton 
becomes even more striking. | 
Wasmann has given an excellent account of the ecitophilous 
Staphylinidae of Brazil! In two more recent papers he de- 
scribes a couple of staphylinids living with Eczton carolinense.” 
In his former contribution Wasmann distinguishes a number 
of ecitophilous genera (Ecitomorpha, Ecitonides, Mimeciton, 
Ecitonilla), which comprise some very remarkable mimics of 
the Ecitons with which they live. The form taken by myself 
is probably the representative of a new genus and is an addi- 
tional case of mimetic adaptation somewhat less perfect than the 
genera described by Wasmann. It is, nevertheless, an admi- 
1 Die Ameisen- und Termitengáste von a I. Theil, Verh. k. k. Zool. Zoot. 
Gesell. Wien. (Jahrg. 1895) pp. 1-45, 7 A 
2 Ein neuer Ecitongast aus Nord-C ina dnm Entomol. Zeitschr. piu: 
Heft ii, pp. 280-282 ; and Ein neuer Gast von Eciton carolinense, Deutsche Entom 
Zeitschr. (1899), Heft ii, ei 409, 410. The species are Ecitonusa euro 
. Was 
und E. Foreli, Was 
