106 
Psyche 
[April 
PECTINATE ANTENNAE IN THE GEOMETRIC 
(LEPIDOPTERA). 
By Wm. T. M. Forbes, 
Cornell University, Ithaca, N. Y. 
The present note is the summary of an analysis of antennal 
characters in the Ennomid Geometridae, for which there seems 
to be no present hope of publication. 
The Geometridae and especially the Ennomid (Boarmine) 
series, have always been notorious for the plasticity of their 
characters and the difficulty of their classification. The present 
study of antennal characters has developed out of Bodine’s 
work (Trans. Am. Ent. Soc. 23, 1, 1896) on the Lepidopterous 
antenna, and has, I believe brought some significant and useful 
characters to light. 
This discussion includes only the genera with pectinate male 
antennae. In the Geometridae the simple antenna is not primitive, 
but has been several times produced by reduction. For the 
present it is not possible to place all these genera, but pupal and 
other characters will throw light on their relationships. 
Bodine recognizes five types of antennal organs: three 
lengths of setae, cones, and pit-organs. In the Ennomids the 
pit-organs seem of little use in classification, and the two types 
of generally distributed setae (his types 1 and 3) are not easily 
distinguished; the presence and arrangement of the long single 
setae which he calls type 2, and the thin-walled sensory cones — ■ 
type 5, — give good characters. 
The following grouping may be made: 
Series I: Pectinations naked; cones on shaft. 
There are three subdivisions of this type, corresponding to 
two natural groups, and a somewhat heterogeneous remainder. 
1. Pectinations each with a single distinct seta of type 2, 
not obscured by long setae of type 3; pupa with two strong spines 
on the cremaster, with dorsal groove (between abdominal seg- 
ments 9 and 10) well developed; moth slender, wing normally 
with fovea. Antenna usually with a long simple apex. 
