The saw flt . 
493 
The tenthredo femorata is, as the name imports, bur- 
dened with two large thighs; the whole infect is black, 
except the antemue and tarfi of the feet, which are yel- 
low f. 
The tenthredo lufluofa alni. This quiet, melancholy, 
and beautiful fly is found among alder plantations, and is 
often fatally entangled in the clammy juice that iffues 
from their leaves. The head and trunk are of a fine yel- 
lowifh brown ; the antennas a more dulky ihade of the 
fame colour, and the eyes blue : The body is coal black ; 
the fegments of a brownifh yellow ; the wings are of a 
pale yellowiih brown, with little yellow riflings upon their 
fibres, and a margin of yellow 
There are no lefs than fifty-five fpecies of the tenthre- 
do enumerated in the Linnuean fyftem ; but the Swedijh 
naturalift feems himfelf to fufpedt, that fome kinds are 
twice mentioned. Colour, though an obvious, is no cer- 
tain chara&er of infefls. In fome, it differs with the fea- 
fon, in others, with the fex ; and in all it glows accord- 
ing to the creature’s health and vigour. 
V Syft. Nat. fpec. i. £ Baibut’s Gen, InfetS. p. 
