200 INSECTS AFFECTING DOMESTIC ANIMALS. 
THE SQUALID Duck LOUSE. 
(Lipeurus squalidus Nitzsch. ) 
According to Denny, this species was referred to by Fabricius under 
the name of Pediculus anatis, and 1t seems extremely probable that it 
was referred to under other names by many of the 
early writers, since it is So common on many species 
of ducks that it is hardly possible that it should 
have been entirely overlooked. The first definite 
reference to it, however, is the description by 
Nitzsch in 1818; and, more fortunate than some of 
the related species, this has been allowed to hold in 
all subsequent works, and so far as we know there 
are no synonyms for its specific name. 
It is a very abundant and common species and 
occurs on a great many different species of ducks, 
both wild and domesticated; indeed, so generally 
does it occur on the different species of the genus 
Anas and related genera that we may almost say 
that it is common to all species of the family inelud- 
eA ing the ducks. r 
es It is quite characteristic in appearance, and not 
“E-*® likely to be confused with other species on the same 
WHE birds. It is about 4 mm. (one-sixth inch) in length, 
elongate in form, and of a light yellowish color, with 
Fie. 122.— Lipeurus Mark border to the head, thorax, and abdomen. On 
squatidus—enlarged the latter this border is broken into a series of quad- 
Ure. vate patches corresponding with the segments. The 
young lack the definite markings of the adults, but have nearly the 
same general outlineof body. The annexed figure will doubtless enable 
anyone to determine with certainty as to specimens taken from ducks. 
Lipeurus anseris Gurlt. 
Under this head is recognized a species which is said to differ from 
the anseris of Linnzus and other authors, which is referred to jejunus 
of Nitzsch. It was described from specimens taken from the domestic 
goose, but would appear to be rather a rare species since it has not been 
generally recognized. We insert it upon the authority of Piaget, who 
Seems to consider it as unquestionably distinct from related species, 
though apparently in doubt as to the real form from which the descrip- 
tions were made. 
THE LIPEURUS OF THE GOOSE. 
(Lipeurus jeyunus Nitzsch. ) 
It is generally accepted that Redi had this species in hand as one 
of the different parasites which he figured, and it has certainly been 
