138 
REVIEWS. 
figures in Professor Jones’s book are reduced copies of those which occur 
in the works of Sir J. G. Daly ell, whilst others are so disfigured as to render 
the recognition of the source whence they have been obtained a matter of 
considerable difficulty. Thus, in Plate I., the artist, intending to re¬ 
present Stomobrachium octocostatum, has introduced in its stead an in¬ 
correct figure of what appears to be Thaumantias lucifera. In both of 
these Medusae the reproductive glands are of a yellow tint, but in the 
figure to which we have referred these organs are painted of a brilliant 
scarlet. Pew would recognise as Aplysia depilans the strangely coloured 
monster represented in Plate VIII., where also, under the name of Buc- 
cinum, may be found a hideous illustration of what is probably Fusus 
corneus. 
A brief dissertation on the importance of becoming acquainted with 
the facts of science, and the danger of indulging in speculative opinions, 
forms a not inappropriate conclusion to Professor Jones’s Manual, which 
is dedicated to the Members of the London Institution, and left to the 
merciful consideration of his lady friends. 
The Student’s Manual oe Geolouy. By J. Beete Jukes, M. A., 
P. E. S., &c. &c. Edinburgh: Adam and Charles Black. 1857. 
This book was originally designed, as the author informs us, to have 
been written by himself and the late Professor Porbes; and in conse¬ 
quence of his death, the entire task devolved upon Mr. Jukes alone. 
The design of the work is excellent, consisting of three parts—Geog¬ 
nosy, Palaeontology, and Geology proper, or history of the surface of the 
globe. The science of Geognosy is divided by Mr. Jukes into two 
branches—Lithology and Petrology (or Fetralogy). By Lithology Mr. 
Jukes understands all that relates to the mineral structure of rocks; 
and by Petrology, all that relates to the structure, in a mechanical 
sense, and arrangement of rock masses. 
The Manual is, on the whole, a valuable addition to our list of geo¬ 
logical text-books, and we are certain that the author will not be dis¬ 
pleased at our pointing out some minor blemishes, the removal of which 
in a future edition will add greatly to the value of the work. He has, 
with more honesty than prudence, published a formidable liskof Errata 
et Corrigenda , with the following preface:— 
u My excuse for the number of the following corrections must he the circumstances 
under which the book has been written and the proof-sheets corrected: at odd times, 
namely, in the intervals of other occupations, on wet days in country inns, in railway 
carriages, in remote parts of the country, where I could not refer to the rest of what I 
had written, and while so engaged in other matters that I could not recollect it. I only 
discovered many of those noticed while preparing the Indexes, and fear some others may 
still remain, which have escaped my attention.— Author.” 
