18 
THE BRITISH WOODLICE, 
"SCHEME OF CEASSIFICGATION. AND 
SYNOPSIS 
OF “GENERIC. CHARACEERS: 
Order—ISOPODA. 
7 ribe—ONISCOIDA. 
Section I.—LIGIZ. 
The Two Divisions of the Tail Appendages alike in Shape. 
(A.)—Flagellum with ro or more joints ; tail appendages 
wholly visible ; head without lateral lobes - 
(1.)—Abdomen broad ; body large ; habitat, 
the sea-shore - 
—Abdomen narrow; habitat, wet moss - 
(B.)—Flagellum with less than 10 joints; head with 
small lateral lobes, tail appendages partly covered 
(3.)—Abdomen narrow; eyes compound ; 
flagellum usually with more than 3 
joints - - - - 
(4.)—Abdomen narrow ; eyes simple or want- 
ing; flagellum with 4 joints - - 
(5.)—Abdomen broad (comparatively) ; eyes 
simple; back with longitudinal ; 
ridges ; flagellum with 3 joints - 
Section II.—ONISCI. 
LIGIIDAE. 
Ligia. 
Ligidium. 
TRICHONISCIDA. 
Trichoniscus. 
Trichontscotdes. 
Haplophthalmus. 
The Outer Divisions of the Tail Appendages Broader than the Inner. 
(A.)—Tail appendages projecting when the animal is 
walking - - - - - - 
(a.)—Unable to roll up into a complete ball. 
(6.)—Flagellum with 3 joints; abdomen 
broad ; head, with lateral lobes - 
(7.)—Flagellum with 3 joints; abdomen 
narrow ; head without lateral lobes - 
(8.)—Flagellum with 1 joint; eyes wanting ; 
abdomen broad; habitat, ant’s nests 
(9.)—Flagellum with 2 joints; abdomen 
broad ; frontal lobe projecting - 
(10.)—Flagellum with 2 joints; abdomen 
narrow - - - - 
(b.)—Able to roll up into a complete ball. 
(11.)—Flagellum with 2 joints; antennae 
folded together over the thorax when 
the animal is rolled up into aball_ - 
(B.)—Tail appendages not projecting when the animal 
walking - - - : 
(12.)—Flagellum with 2 joints; antennae 
hidden or carried at the sides of the 
head when the animal is rolled up 
into aball - - - - 
ONISCIDA. 
Oniscus. 
Philoscia, 
Platyarthrus. 
Porcellio. 
Afetoponorthus. 
Cylisticus. 
ARMADILLIDIIDA, 
Armadillidium. 
