INTRODUCTION. /y 
1. The luUform or pre-eminently typical, wliicli 
are smooth and destitute of horns or other excres- 
cences; for example, the caterpillars of cabbage 
butterflies. 2. Raptorial, or sub-typical. These 
are the type of evil, having the body covered with 
pungent spines, &c. ; for example, the caterpillar of 
the peacock butterfly. 3. Natatorial or Anopluri- 
form; caterpillars of the Hesperidae, and Hawk- 
moths. 4. The Suctorial or Vermiform, called also 
the Onisciform; example, caterpillars of Polyom- 
matus. 5. Rasorial or Thysanuriform ; head and 
tail armed with spines ; for example, the caterpillar 
of Pap. Cassis3. 
However much deserving of commendation cer- 
tain parts of these classifications may be, they are 
far from being satisfactory on the whole. In a race 
of insects having the parts of the mouth, which 
afibrd such valuable characters in most other groups, 
so similar to each other, it can only be by a judi- 
cious combination of characters derived from all 
the difi*erent states, and not from one of them 
only, that a proper arrangement can be effected. 
The state of our knowledge is not at present such 
as to render an attempt of the kind advisable. A 
long and careful investio-ation of larvae in their native 
haunts, — a more diligent search than has yet been 
made for the perfect insects, particularly of the 
smaller kinds, in foreign countries, must previously 
be undertaken. In scarcely any other department 
of exotic entomology has so little progress been 
made as in this. This has been partly owing to the 
