REVIEWS. 
181 
science advanced. We think, too, that the wants of the reader are far better 
supplied than the modest author imagines when he refers, in illustration, to 
the “ old woman in New England who asked a bookseller to supply her 
with the cheapest bible in the largest possible print.” We look upon this 
last book of Sir Charles Lyell’s as a perfect model, for it contains almost 
everything that the geologist who is not engaged in advancing the study of 
geology should know, while for the student it contains everything which 
he requires. We admire, too, the way in which the author has been at 
pains to illustrate everything, conscious, doubtless, from long experience, 
of the great necessity of having multitudes of wood- engravings in a text 
which will be chiefly read by those commencing the study of this most 
entrancing and wonderful science. This will be the more evident when we 
say that the text extends over 600 pages, and the woodcuts reach no less a 
number than 630. It would, of course, be impossible to review a book like 
this beyond merely stating our opinion of it, as we have done. But, how- 
ever, we may refer to one or two sections, showing how the author has 
brought in the most recently ascertained facts within the compass of his space. 
Especially i3 this shown in his references to Carpenter and Wyville Thom- 
son’s idea of the present existence of the chalk formation, an opinion founded 
on the presence in the Atlantic of a few chalk shells hitherto considered 
fossil. “We must be careful,” says Sir Charles Lyell, “not to overrate the 
points of resemblance which the deep-sea investigations have placed in a 
strong light. They have been supposed by some naturalists to warrant a 
conclusion expressed in these words : 1 We are still living in the Cretaceous 
Epoch ’ — a doctrine which has led to much popular delusion as to the bear- 
ing of the new facts on geological reasoning and classification. The reader 
should be reminded that we have been in the habit of founding our great chro- 
nological divisions not on foraminifera and sponges, nor even on Echinoderms 
and corals, but on the remains of the most highly organised beings available 
to us, such as the mollusca, these being met with in stratified rocks of 
almost every age. In dealing with the mollusca, it is those of the highest or 
most specialised organisation which afford us the best characters in propor- 
tion as their vertical range is the most limited. Thus the Cephalopoda are 
the most valuable as having a more restricted range in time than the Gastero- 
poda, and these again are more characteristic of the particular strati graphical 
subdivisions than are the Lamellibranchiate bivalves, while these again are 
more serviceable in classification than the Brachiopoda, a §till lower class of 
shell-fish, which are the most enduring of all. When told that the new 
dredgings prove that ‘ we are still living in the Chalk Period ’ we naturally 
ask whether some cuttle-fish has been found with a belemnite forming part 
of its internal framework F or have Ammonites, Baculites, Hamites, Turri- 
lites, with four or five other Cephalopodous genera characteristic of the 
chalk, and unknown as tertiary, been met with in the abysses of the ocean ? 
Or, in the absence of these long extinct forms, has a single spiral univalve or 
species of cretaceous Gasteropod been found living P Or, to descend still lower 
in the scale, has some characteristic cretaceous of Lamellibranchiate bivalve 
. . . been proved to have survived down to our time ? ... It has been very 
generally admitted by conchologists that out of a hundred species of this 
(Brachiopod) tribe occurring fossil in the Upper Chalk, one, and one only, 
VOL. X. NO. XXXIX. O 
