1899] A PICTURE-GALLERY OF THE ISOPODA 293 
But since the time of Latreille there have been discovered in the depths of the 
sea and elsewhere, numerous species of Isopoda, in which the inequality and 
dissimilarity of the legs attached to one and the same body is carried to an 
almost extravagant extent. This will be seen at a glance by any one who only 
turns over the excellent plates with which Sars’s work is illustrated throughout. 
The plates of the present volume are 104 in number. They would often be 
a kind of revelation to the casual observer, who seeing sees not, as he gazes 
at the animals themselves in the specimen glasses of a museum. The student 
also, preparing to dissect a rare isopod, should certainly first make himself 
acquainted with these drawings before attempting the severance of minute and 
delicate organs, which may be rendered undecipherable by one rash thrust of 
an ignorant needle. 
As regards classification, it may be remarked that Professor Sars retains the 
Tanaidae among the Isopoda. This has the great merit of present convenience, 
whether or not at some future date the separatist party may succeed in detach- 
ing this group from its near allies. Most of the species of it, according to 
Sars, construct for themselves abodes of mud, into which they may wholly 
withdraw their bodies. On the English coast, however, there is one species 
pretty frequently to be found, along with the Gribble, in the honeycombing of 
submerged timber. On the group at large the Professor makes another observa- 
tion, which is of much interest to the collector. ‘ They all, moreover,” he 
says, “exhibit this peculiarity, namely, that in reaching the surface of the 
water they remain floating, without being able to re-immerge their bodies, 
whereby the discovery of the generally very small and inconspicuous specimens 
is essentially facilitated. On placing some muddy clay taken from greater 
depths, in a shallow vessel, and stirring up the mud, they will very soon appear 
floating on the surface, like small white pins, and may easily be taken up for 
a closer examination.” Naturally this mode of discovery will apply to the 
tenants of mud from small depths as well as great, and in some localities to 
the sand-dwellers of the sea-shore. 
To the elucidation of the tribe Epicarida, it will be found that the work 
under review has made a very valuable contribution. In this tribe not Alps on 
Alps, but shrimps on shrimps arise. The Isopoda of which it is formed, in all 
sorts of insinuating ways, implant and engraft themselves upon other crustaceans, 
in the process assuming oddities of form, distortions and degradations, in 
pleasing but often extremely puzzling variety. There is plenty of work 
apparently still to be done in this branch of investigation, but the intricacies 
of it have been wonderfully disentangled by the labours, whether in conflict or 
agreement, of Giard and Bonnier, of Kossmann and of Sars. 
In the great variety of species, normal and abnormal, which are shown to 
belong to the isopod fauna of Norway, it is singular that the Sphaeromidae 
find no mention. This is a family of extremely extensive distribution in the 
sea, and is represented even in fresh water. To one of the species incidental 
allusion was made at the beginning of this notice, simply because it is among 
the most familiar of British marine Isopoda, so that the absence of the whole 
family from Norwegian coasts and waters may well cause surprise. 
The volume just completed is published by the authorities of the Bergen 
Museum. To them, therefore, as well as to the author, science is much indebted. 
There is one small but not unimportant improvement by which they might 
easily increase the obligation. The seven double parts of the original issue 
bear dates extending over four years, from 1896 to 1899. When the wrappers, 
which are of an essentially unstable character, are removed, the bound volume 
will contain the latter date alone. Since it teems from one end to the other 
with original observations, and with definitions and descriptions of new genera 
and species, the reader ought surely to be supplied with some means of ascer- 
taining the true dates of its several parts. This could have been best effected 
by printing month and year of issue at the foot of the last page of the text, 
