Frenulum of the Lepidoptera. 123 
Since this examination has been in progress Prof. 
Comstock in his essay, “ Evolution and Taxonomy,” 
published in 1893, and subsequently in his “ Manual for 
the Study of Insects,’ 1895, has formulated a classification 
of the Lepidoptera principally based on wing-characters. 
He proposes a division of the Order into two Suborders, 
Frenate and Jugate, the former of which embraces all 
those species which either possess this structure or appear 
to be descended from groups formerly possessing it, whilst 
the Jugatz have the wings united by a lobe or jugum. 
The latter Suborder consists only of the Hepialidz and 
Micropterygidz, which are certainly some of the most 
primitive of the Lepidoptera, and in other respects, as 
well as in the possession of the jugum, are clearly related 
to the Trichoptera. 
With the merits of this classification we cannot deal, 
but will simply observe that the frenulum is scarcely so 
persistent or general in its occurrence as to give its name 
to a broad division of the Lepidoptera. 
Mons. E. L. Ragonot (Essai sur la Classification des 
Pyralites, 1891), Sir George F. Hampson (Fauna of 
British India—Moths, 1892-96), Mr. E. Meyrick (Hand- 
- book of British Lepidoptera, 1895), and Dr. A. S. Packard 
(Monograph of the Bombycine Moths of America North 
of Mexico, 1895) have all considered the frenulum with 
great care, employing it with other characters in dis- 
crimination of genera, whilst they do not attribute to it 
the supreme importance claimed by Comstock. 
Speaking generally, and with certain exceptions to be 
mentioned later, we find in those species which possess 
the frenulum that the males have a strong single bristle, 
springing from the costal nervure of the hindwing, and 
passing through a loop, or sometimes into a pocket, situ- 
ated on the costal nervure of the forewing; that the 
females usually possess two or more slender and weak 
bristles upon the hindwings in place of the single bristle 
of the male insect, and that these bristles, instead of 
passing into a loop, are simply thrust into, and entangled. 
among, a group of large raised scales or hairs situated 
between the costal and median nervures of the forewings. 
And here at the outset we meet with a difficulty 
arising from the confusion of names applied by different 
authors to the various parts of this appliance. Whilst 
De Geer speaks of the bristle under the name of pot! and 
