96 CERTAIN PARASITIC INSECTS. 
are as long as the head is broad at the place of their inser- 
tion ; the second joint is much longer than the first ; the third 
and fourth are together as long as the second, while the fifth 
is a quarter longer than the fourth joint. The mandibles are 
narrow, acute, with two unequal fine teeth. 
To the genus Trichodectes belongs the T. subrostratus 
Nitzsch? (Fig. 27) identified by Dr. Burnett as probably 
the same as the European species. It is a 
parasite of the common cat. The front of 
the rather square head is elongated trian- 
gularly, with the apex ending in two acute 
spines on the under side of the head. The 
antenne are three-jointed, with the middle 
joint a little longer than the last. The 
abdomen is oval, and the animal is whitish, 
with the head and thorax pale honey- . 
yellow. The other species lives on the 
goat; it seems to be undescribed, and may 
be called the Trichodectes capre (Fig. 23) ; 
it is closely allied to T. longicornis of 
Europe, but the head is not hollowed so much in front and is 
rather broader, while the third joint of Fig. 28. 
the antenne is more slender than in that 
species. It is reddish yellow, while the 
abdomen is edged with red, and is barred 
transversely with reddish brown. 
The Saddle-back Gull (Larus ma- 
rinus) is infested by an undescribed 
«species of louse which we may call Ool- 
pocephalum lari, Pl. I, fig. 1. It is dark 
brown and oval in form, with the head 
deeply indented in the middle; the an- 
terior lobe, or clypeus (made too small Louse of the Goat. 
in the figure), is twice as broad as long, with the basal half 
of che head a little wider than the head is long. The slen- 
der filiform antenne are three-jointed, the last joint some- 
Fig. 27. 
Louse of the Cat. 
