THE IDOTEID@ 373 
forotus is obvious ; but the antennules in Cheetilia are placed 
immediately above the antenne, asin Hdotia.’ in Chetilia 
ovata, Dana, the sixth pair of legs are described as being 
‘twice as long as the entire animal, terminating in a very 
long bristle-like extremity, which consists of numerous 
joints. The seventh pair has also a multiarticulate ex- 
tremity, which is, however, quite short.’ Dana thought a 
separate family Cheetiliide necessary for this genus. 
Arcturides, Studer, 1882, in general appearance and in 
the length of the second antennz approaches Arcturus, but 
the short-jointed limbs are all very nearly alike, though the 
first are shortest, and the three following pairs a little 
more prehensile than those to the rear. In the southern 
Arcturides cornutus, Studer, the head has a pair of frontal 
horns, and is not articulated with the first pereeon-segment 
though divided from it by a suture. 
Idotea, Fabricius, 1793, has the second antennz mode- 
rately elongate; the maxilliped-‘ palp’ four-jointed, only 
the last two joints being fused; the limbs of the pereon 
all nearly alike, with the sixth joint not or not much ex- 
panded, but the seventh prehensile. The uropods have on 
the basal plates a raised line near and almost parallel to 
the inner margin, and an apical plumose seta, which is 
concealed under the terminal plate. The species are very 
numerous, and several additional genera have been pro- 
posed which Mr. Miers does not think worthy to be 
upheld. 
Idotea marina (Linn.) is the name he adopts for that 
which Bate and Westwood describe as Idotea tricusyidata, 
Desmarest, and [dotea jelagica, Leach, and which has also 
been called by a dozen other names. It is very abundant. 
Its distribution appears to be almost cosmopolitan. In 
size and colour it is extremely variable. Idotea metallica, 
Bosc, which seems to have as great a range over the world, 
is, however, not recorded from British coasts. Jdotea 
emarginata, Fabricius, is common in British waters, but 
not like marina on the shore, and the same may be said 
of Idotea linearis (Linn.), with which Mr. Miers com- 
bines the curiously striped Idotea sexlineata of Kroyer. 
