2/6 SIREX. 
The larva, which measures about an inch and 
quarter in length, is of a yellowish white colour, 
and inhabits decayed firs and pines: at first view 
it bears some resemblance to the larvae of the 
beetle tribe, but is thinner in proportion, and 
furnished at the tip of the abdomen with a short 
black spine or process. It changes to a chrysalis 
in July; first enveloping itself in a slight silken 
web of a whitish colour t the chrysalis is of a 
lengthened shape, with the antennae, legs, and 
terminal tube or process very distinctly charac- 
terized. If the change to chrysalis takes place in 
summer, the fly proceeds from it in the space of 
about three weeks; but if at the close of autumn, 
the animal continues in chrysalis the whole winter, 
emerging in the following spring. The male insect 
is considerably smaller than the female, and may 
Ije farther distinguished by the want of the caudal 
tube or process, so conspicuous in the female in- 
sect: the tip of the abdomen is also of a black 
colour. The eggs, which are deposited by the 
female in the decayed parts of the trees above- 
mentioned, are very small, and of a lengthened 
oval shape with pointed extremities. 
Sh'e.v Coiumha is an American species, and is 
distinguished by its black body, marked by test- 
aceous bands. 
Sirex pygmccuo is one of the smallest of the 
Kuropean species, being, according to Linnaeus^ 
about the size of a gnat, with a black abdomen, 
marked by three yellow bands, the middle of 
which is interrupted. It is found in Sweden. 
