124 FEATHER-LICE OF DUCKS, ETC. 
Its color is white and very transparent; it is ornamented 
with a number of black spots. 
Trinotum luridum Nitzsch. 
Most of our ducks are more or less badly infested with 
this large feather-louse, which measures 4 to 5mm. inlength. 
It is a well-marked species, as can be seen in the illustration 
(fig. 100). 
Trinotum conspurcatum Nitzsch. 
This species is said to be found upon the goose and 
swan. 
Trinotum lituratum Nitzsch. 
This peculiar animal is not uncommon upon the domes- 
tic goose, but has also been repeatedly taken from Green 

Fig. 101.—Biting-louse of ducks, etc., and tarsus. Greatly enlarged. Original. 
Teals. It is white and almost transparent. The illustra- 
