THE GENUS ENNOMOS (SENS. STR.). 53 
THE GENUS ENNOMOS (Sens. Srr.), WITH AN ACCOUNT 
OF SOME OF ITS HYBRIDS. 
By J. W. H. Harrison, B.Sc. 
(Puates I. anp II.) 
(Continued from Entom. xlix., p. 29.) 
(b) The female bears much the same relation to the hybrid 
male as the female quercinaria does to its male—that is, we have 
the same difference in secondary sexual characters. When this 
is said there is little else to add, except that the female genitalia, 
in all respects, Ostiwm, Ductus burse, Bursa copulatrix, are 
exactly intermediate to the two species, as can be seen by 
reference to fig. 3c. Possibly, however, the chitinous signum 
on the Bursa is nearer the almost obsolete signum of subsignaria 
than to the thicker spiculated one of quercinaria. 
In the above descriptions it will be seen that, in spite of what 
was said above to the effect that the hybrid larva was nearer 
subsignaria, there has been a constant emphasis on quercinaria 
characters. This is simply becanse upon a featureless, snowy- 
white ground very minute differences are accentuated. Wherever 
the two forms show definite characters, then the characters 
derived from subsignarius preponderate. The same phenomenon 
has been discussed* in the case of Jthysia hybrid merana 
(=I. zonaria x P. lapponaria). To a casual glance the insect 
is wholly under zonaria influence; but when its characters are 
analysed it is found to be nearer lapponaria. 
(c) Gynandromorphic Specimen.—This specimen is a very 
peculiar one, and the significance of its peculiarities is discussed 
at the end. At first sight it is merely a male specimen with the 
left antenna female. Dissection and close examination betray 
much more interesting characters than that. The genitalia 
(fig. 4), although nearly so, are not quite purely male; the right 
lobe of the uncus is replaced by a fully developed right ovipositor 
lobe, whilst the gnathos on the same side is greatly distorted, 
and acts as if it were homologous to the female directing rods. 
In addition, whilst the coloration of both sides of the body 
is male, the shape of the right wings is female ! 
(d) Asymmetrical Specimen. —This individual, too, is an extra- 
ordinary individual, the right side being exactly that of a normal 
hybrid, whilst the left side is pure subsignaria. 
The problems raised by this specimen are reserved for 
discussion in the conclusion. Its genitalia present the same 
division of characters as those exhibited externally, as may be 
seen from fig. 8, which shows the furca and the penis, the left 
side being that of the hybrid, whilst the right is evidently that 
of subsignaria conforming itself to the structure of the left. 
* Harrison (1913). Lep. comparée p. 112 
