2B8 
[October 
vitta, and its apex is triangularly emarginate; the 8th ventral is tipped with a 
slender acute spine; and the anal appendages are short, conical, and pale-red¬ 
dish-brown, scarcely tipped with black. 
Length 9 mill. Exp. % 37—38 mill. 9 42—43 mill. Superior appendages 
% 1 mill. 
Two % , two 9 , both pairs taken in coitu in June, not far from a 
saw-mill. Agrion hinotatum Walsh, occurred only on and near log- 
rafts from Wisconsan, at two different points distant over two miles 
from each other, whence I infer its true habitat to be Wisconsan. 
Dentiferum differs from s^ignafum Hagen, in the pale color not being 
“ yellow,” in the superior % appendages being scarcely “ subdolabri- 
form,” in the inferior appendages not being black,” and in the ptero- 
stigma not being “ fuscous.” Tn some respects this species agrees bet¬ 
ter with AgrionpoUutum Hagen. Greorgia is the northernmost State in 
which either dgnatum or pollutum has been taken, and the 9 of signatum 
is as yet undescribed. The medial tooth on the superior S appendage 
of dentiferum strikingly recalls some species of Gromphus, ffraternm, 
adelphus and va^^tu^i) There is no better or more reliable character in 
Odonata than the shape of the % abdominal appendages. It is singu¬ 
lar that in the difficult Orthopterous family of Locustariae Latr. (= 
Grryllidae Leach,) although the shape of the % anal appendages varies 
almost in every species and is very constant in each, precisely as in 
Odonata, yet Orthopterists have as yet made no use of so important 
and definite a character. 
GfOMPHUS. 
Gr. FRATERNUS Say. This species is described in the Monographic 
(p. 125) from two small immature specimens from New York, one % 
one 9 , the 'S with its abdominal appendages mostly broken off. Con¬ 
sequently these last have neither been figured nor described. I note 
the following points in which the description differs from my Illinois 
specimens, and supply the deficiency in regard to the abdominal ap¬ 
pendages. Say’s brief description of this species would apply 
nearly as well to half a dozen others. Nobody but those who, like 
myself, have examined many scores of specimens of particular species 
of Gomphus from one and the same localitj/^ can form any idea of how 
constant the size always is and how constant the coloration is except in 
very immature individuals, and what minute differences of coloration are 
of specific value. The only very remarkable variable character in this 
