108 
defined in nature, and they are subdivided into secondary 
groups, and are also united in some instances by forms of 
life which cannot well be placed in any particular one.” 
We presume these “ latter forms of life’’ are those called 
“intermediate groups,” which are “(1) the Tunicata, 
which have a more or less leathery or cartilaginous cover- 
ing sac.” “They may be placed in the neighbourhocd of 
the Vermes and Mollusca in their classification.” “(2) 
The Molluscoida, which have the body with shells placed 
differently to those of the Mollusca, or have a tubular or 
shell-like covering.” ‘The Bryozoa and Brachiopoda are | 
included in this group, and in their structures, embryonic 
and adult, trey show resemblances to those of Vermes, | 
Mollusca, and Tunicata.” 
The chapters on Mollusca and Tunicata are by Dr. 
Henry Woodward; the Bryozoa and Brachiopoda by | 
Agnes Crane; the introduction to Insecta and the account 
NATURE 
~ bs 2 , ts ; we 4 
[Dec. 1, 1881 
of the order of the Hymenoptera is from the pen of Mr. 
Dallas, and the chapter on the order of Coleoptera is by 
Mr. Bates. 
will find no hint that the Arthropods are jointed-limbed 
animals containing the Crustacea and Arachnids, unless 
incidentally when Mr. Dallas is describing the true 
Insect type. 
It is scarcely necessary to state that within the limits 
at his disposal Dr. H. Woodward has given a very 
interesting account of the Molluscan forms. We are 
glad to note too that he has devoted a good portion of 
his space to an account of the Cuttle-fishes, which is more 
exciting and interesting reading than the necessarily brief 
accounts of such families as those of Cancellariade and 
Pyramidellidz. The chapter on that “intermediate 
type,” the Tunicata, is poor indeed, and not what we 
should have expected from its author. Surely we have 
The Leaf-finned Sea-horse. 
learned something more of this group since the writings 
of Forbes and Savigny. 
The chapters on the Brachiopoda and Bryozoa by 
Agnes Crane appear to be extremely carefully written. 
The illustrations—many of them—are refreshingly new, 
and taken from the best of sources. We altogether dis- 
agree with the authoress as to adopting the name of 
Bryozoa for the group she calls Sea-mosses, but she 
states the case for and against the use of the term Polyzoa 
most fairly; and nowhere have we met a more neatly 
compiled account, brought down, too, to the very latest 
date of this group—even the facts brought to light by the 
expedition of the Challenger are alluded to therein. 
The introduction to the group of Insects is remarkably 
well done. The classification is primarily based on the 
presence or absence of a perfect metamorphosis, and the 
secondary divisions are based on the structure of the 
mouth. As for certain small groups of insects which 
undergo no metamorphosis at all, ‘‘ They may be resi- 
dues of groups formerly more numerous and abundant, 
in which case they ought probably to be kept distinct 
from the other existing orders of Insects,” or as we prefer 
to think, “‘they may be degraded representatives of the 
orders to which they appear to be most nearly related.” 
The account of the first order on the list, that of the 
Beetles, is written by H. W. Bates, and few possess more 
knowledge of the many forms that compose this group. It 
need not be said that he does not attempt to treat of the 
80,000 and upwards of known forms in the fifty pages at 
his service, but from what he tells us of the habits of 
those he does describe, we feel our interest in the subject 
increasing, until, when we come to the account of the 
Ladybirds, “ upwards of 1500 species of which are known,” 
we feel sorry that we have come to the very last line long 
ere the author had evidently come to the last of his 
subject. 
In passing we may note that the reader " 
