Dr. T. A. Chapman on Heterogyna penella. 149 
ment) and tapers to the posterior extremity. The dorsal 
anterior margins of the abdominal segments are rough 
with longitudinal wrinkles on the fourth becoming very 
definite spines which on the later segments up to the 
eighth are placed two, three, and four deep, in irregular 
alternating rows. There is a certain amount of lateral 
flanging (as in Zygena and Procris), that is,a soft wrinkled 
area leaves the harder parts in some degree as dorsal and 
ventral plates. In this flange some trace of the lateral 
yellow band of the larva still remains. The appendages 
are extremely polished and smooth, and are easily separ- 
ated from each other. There is a large dorsal head piece, 
no trace of maxillary palpi; all seven abdominal spiracles 
are exposed, 
For emergence the pupa projects from the cocoon 
through a loose valvular opening and remains there after- 
wards, 
On dehiscence the eye pieces separate from the dorsal 
head pieces, and remain attached in front. In an empty 
pupa case the labrum, mandibles and _ well-developed 
labium are all very distinct. 
In the male imago, the frenulum is interesting as con- 
sisting of a bundle of hairs, which are all separate at their 
bases, but unite into a solid bristle above ; the frenulum 
has the appearance of being compounded in many species, 
but I do not remember it to have been actually resolved 
into its constituent hairs for a portion of its length in any 
other species I have observed. 
The general surface of the wing-membrane is tinted as 
with a wash of indigo. In the forewing, a small portion 
at the base of the inner margin, corresponding with the 
jugum in the Jugatz, is folded over on to the wing, the 
fold being clear of tinting and studded, as the rest of the 
wing is not, with very fine hairs. The corresponding 
portion of the hindwing is much larger, and is similarly 
marked off by a colourless line or area, from the base to 
the hind margin, where there is a notch. 
The male pupa, the egg, larva and, I think, the imago 
all point to a close relationship to the Zygenide, but at a 
considerably lower level, as is chiefly evidenced by the 
larval tubercles and prolegs. The pupa also is probably 
lower, having the parts even less firmly soldered. Though 
one does not look to the female pupa for much light 
on the affinities of this form, owing to its being so specially 
