22 The Developmental Characters of
bidentata, which have eight claspers, and Metrocampa mar-
garitata and Ellopia fasciaria, which have only six; and I
would suggest that the ontogenetic development of these
species should be studied carefully, with special reference to
the number, relative lengths, and positions of the abdominal
legs. The Drepanulidae and Pseudo-Bombyces have in most
cases the full number of legs, but the last pair (13th seg-
ment) is sometimes absent, or replaced by forked appendages.
The majority of the Nocture larvae have sixteen legs, but as
we approach the end of the group this number becomes
variable, as will be seen from the following list compiled from
Stainton's 'Manual':—
TRIFIDAE.
Bombyciformes.—Larva with 16 legs.
Genuinae.—Larva with 16 legs.
Minores.—Larva with 10, 14, or 16 legs.
QUADRIFIDAE.
Variegatae.—Larva with 12, 14, or 16 legs.
Intrusae.—Larva with 16 legs.
Limbatae.—Larva with 16 legs, "but looping the anterior
segments when walking."
Serpentinae.—Larva with 12 or 14 legs.
This fact becomes still more evident, if we make a more
detailed analysis of the latter groups :—
MINORES.
Aconthiidae.
Agriphila.—Larva geometriform, with only 12 legs.
Acontia.—Larva geometriform, with only 12 legs.
(The larva of A. luctuosa is exceptional,
having 16 legs).
Erastriidae.—Larva with 14 legs, half-loopers ; 1st pair
of claspers indistinct.
Erastria.—Larva with only 3 pairs of claspers.
Bankia.—Larva with 2 pairs of claspers, 3rd pair
rudimentary.
Anthophilidae.—Larva with 12 or 14 legs.
Phalaenoidae.—Larva with 16 legs, but two 1st pair of
claspers rudimentary.