FLY. 
3/9 
rioiis formation, and exhibit wonderful examples 
of the provision ordained by Nature for the pre- 
servation of even the meanest and most seemingly 
contemptible of animals. Several are inhabitants 
of plants, feeding during this state on other living 
insects. 
The general form of the Chrysalis or Pupa is 
that of an oval, differently modified, according to 
the species, and formed by the external skin of 
the larva, which hardens round the chrysalis. 
Some species however cast their skin before their 
chanore into the pupa state. 
In this^ division one of the most remarkable 
species is the Mnsca Chamceleon, which is a large 
black Fly, with a broad, tlattish abdomen, having 
the sides of each segment yellow, forming so 
many abrupt semi-bands across that part. It pro- 
ceeds from an aquatic larva, of very considerable 
size, measuring two inches and half in length; 
of a somewhat flattened shape, and of a brown 
colour, with a narrow or slender front, the bodv 
widening by degrees towards the middle, and 
from thence gradually tapering to the extremity 
or tail, which is terminated by a circle of radiating 
or diverging hairs. This larva is common in 
stagnant waters during the summer months, and 
passes into its chrysalis state witliout casting its 
skin, which dries over it, so as to preserve the 
former appearance of the animal in a more con- 
tracted state. 
In this division also stands the JSlusca VermikOy 
a middle-sized Fly, of a somewhat lengthened 
