INTRODUCTION. 
69 
MTth sereral, often rery vi>id and strongly con- 
trasted. Sometimes tliey are distributed in rays or 
longitudinal stripes, at other times in bands which 
follow the contour of the rings ; often in waves or 
spots of regular or irregular figure ; and not imfre- 
quently in insulated points, and numerous other 
forms too complex and varied to admit of being 
here particularised*. It frequently happens that 
the colours of larvae, before their first moult, are 
entirely different from those aftenvards assumed ; 
and in some instances they undergo a considerable 
alteration at every successive change of skin. Dif- 
ference of colour, in indi^dmils of the same species, 
sometimes indicates the respective sexes of the 
future moth ; thus, according to De Geer, the broivn 
caterpillars of a common species, the Yellow Un • 
derwing ( Triphama pronula ) produce males and 
the green ones females. 
Many of these caterpillars are distinguished by 
horns and protuberances of various sorts, which add 
greatly to the singularity of their aspect. The 
curious caudid ajipendages of those of the Puss and 
Lobster moths have been already alluded to, and will 
bo more particularly described hereafter. Several 
have a kind of horn on the hinder extremity, some- 
thing resembling that of Hawk-moth larv®, but 
it is never so long and acute as in the latter, at 
least among British species, but rather assumes the 
form of an elongated tubercle. An example of this 
* Reaumur, Memoirs pour servir a Vldstoire des Insectes^ 
torn. i. page 76. 
