MUSCA TENAX. 323 
found to be completely developed^ or 
formed. It remains, however, a chrysalis 
for about ten days longer, when it 
emerges from its cell, a yellow and black 
fly, called the niusca tenax ; it is com- 
monly seen hovering over flowers, and is 
often mistaken for a bee *. 
* Plate XXIII. 
