THE GIDE J47 
Corallana, to which they have been assigned, but infirmi- 
ties of description have made it impossible for Dr. Hansen 
to decide these cases. It is only by degrees beginning to 
be understood that by naming undecipherable species 
naturalists increase neither the resources of science nor 
their own reputation. 
Family D.—Barybrotide. 
Barybrotes, Schiddte and Meinert, 1879, is the only 
genus. ‘The limbs of the perzeon have the seventh joint 
in the first three pairs forming a strong hook, and all the 
seven pairs by dilatation of the joints or garniture of sete 
are auxiliary to swimming. ‘Two species, /ndus and agilis, 
were instituted by the authors of the genus. Hansen finds 
that these are one and the same, and adopts the name agilis 
as the most significant, but as Indus has precedence in the 
original authority, it should be retained. Schiddte and 
Meinert state that the male has a stiliform appendage on 
the inner side of the inner branch of the second, third, and 
fourth pleopods, which would be a truly remarkable 
feature. But Hansen, who has examined the type-speci- 
mens, declares that neither here nor in any other Isopod 
does such an appendage occur on the third and fourth 
pleopods, it being limited here as elsewhere, to the second. 
A noticeable feature in the species is that the seventh 
segment of the pereeon is almost entirely concealed. The 
animals have only been taken in the open sea. 
Family L.—Aigide. 
To discriminate the young of this family from those of 
the Cymothoidz demands careful scrutiny. It has for this 
purpose to be noticed that in the Atgide the last three 
pairs of perzeopods have the seventh joint rather shorter 
than the sixth, and, though a little curved, not forming a 
hook, whereas in the Cymothoidee this seventh joint is not 
shorter than the sixth and forms a much curved hook. 
When the animals are adult or half-grown the distinction 
is easy. In addition to the character already mentioned, 
