ISOPODA. 113 
Subtribe 2, Arcturidea (Anisopoda Idotzica). 
Fam. 1, Arcturide.—Subfam. 1, Arcturine ; sub- 
fam. 2, Anthurine. 
Subtribe 3, Tanaidea (Anisopoda Oniscica). 
Fam. 1, Tanaidea.—Subfam. 1, Tanaine; sub- 
fam. 2, Liriopine ; subfam. 3, Crossurine. 
Fam. 2, Bopyride.—Subfam. 1, Bopyrine; sub- 
fam. 2, Ionine. 
Of the few divisions, the names of which are printed 
in italics, no representatives have hitherto been de- 
tected in the British Seas. This is the more remarkable 
as regards the entire parasitic family, Cy MoTHOIDz, com- 
posed as it is of three subfamilies, Of the remaining 
extra British groups, the CH2TILIDZ is composed of the 
single genus Chetilia, Dana, with the sixth pair of legs 
exceedingly long and multiarticulate, founded on a Pata- 
gonia species; the TyLIN& is composed of the spiracled- 
branchial Tylos, Latreille, from the shores of the Medi- 
terranean. The ScypHacin&, consists of the genera 
Scyphax, with one species from New Zealand, and Sty- 
loniscus, with two species from Terra del Fuego and the 
Friendly Islands; the ANcrinIN#&, of doubtful location, 
is composed of the genus Ancinus, Edwards; and the 
SEROLIDZ&, composed of the flattened genus Serolis, from 
the Southern Seas, with strong claws to the fore legs. 
Of the subdivisions composing the three subtribes of 
Isopoda proper we can speak with satisfaction; but the 
whole arrangement of the Anisopoda seems to us un- 
natural: thus, referring only to the British groups, we 
consider, Ist, that an arrangement which can group 
together the female of Anceus (Praniza) and Serolis 
must be founded upon entirely false principles. 2ndly, 
that Arcturus, although exhibiting a remarkable modifi- 
cation in its legs and basal segments of its tail, possesses 
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