128 NATURAL SCIENCE [August 
be found in his recent work in Gegenbaur’s “ Festschrift.” The 
Turbinolidae are a standing example of the unreliability of a classifica- 
tion founded upon the supposed difference between an Eutheca and a 
Pseudotheca. They are positively stated on p. 319 to have ‘‘a well 
built theca, whose fibrous elements are set in a direction at right 
angles to those of the septa.” Caryophyllia is regarded as a typical 
Turbinolid, yet the writer has sections of Caryophyllia smithii which 
demonstrate conclusively that there are no such thecal pieces with 
fibrous elements set in a direction at right angles to those of the 
wall. The wall is in fact a typical pseudotheca, formed by the 
coalescence of the thickened peripheral ends of the septa. The same 
must be asserted of Stephanotrochus and others. Remembering that 
the wall of Caryophyllia is a pseudotheca, it is difficult to place 
Flabellum in the same group with it, and Miss Ogilvie’s remarks on 
Flabellum suggest that she has not grasped the meaning of von Koch’s 
argument that its ‘theca’ is in fact an epitheca. 
It would not be difficult to find other materials for criticism, but 
enough has been said to show that Miss Ogilvie’s more general 
conclusions must be received with caution. So long as she deals 
with the matter of her own original observations she is on safe 
ground, and in describing the finer structure of the corallum she has 
added largely to our knowledge, and has opened up a suggestive field 
of research. But she has marred her work by an effort to be too 
comprehensive, and in her attempt to form a complete system she 
has been obliged to rely on characters other than those which have 
been the object of her researches, and therefore has, in our opinion, 
been led into error. However extensive and excellent her work, it is 
not yet sufficient to allow of the making of a wholly new and general 
scheme of classification. But whilst one cannot accept the classifica- 
tion as it stands, one must feel that it abounds in suggestions. The 
suggested lines of descent of living from extinct forms, offer 
most interesting material for enquiry. There is an ingenious, but 
not wholly new, suggestion as to the probable relation of mesenteries 
in palaeozoic corals, involving an explanation of tetrameral arrange- 
ment of septa. The explanation of the nature of the fossula is 
ingenious and probable; unfortunately it is one of those poimts which 
can scarcely be proved by observation. 
In conclusion, the work, though it may have defects, is a most 
useful one; it must always influence other workers in the same field, 
and it is probable that some of the main features of the classification 
will come to be universally adopted. One thing, at least, is certain, 
nobody will henceforth speak of the group of Rugosa. 
G. C. BOURNE. 
R. Hertwic’s TEXT-BOOK OF ZOOLOGY 
LEHRBUCH DER ZooLocin. By Dr R. Hertwig. Fourth improved edition. 8vo. 
Pp. xii. 612, with 568 text-figures. Jena: G. Fischer, 1897. Price in paper 
wrappers, 11 marks 50 pf. ; bound, 13 marks 50 pf. 
IT is just two years since we reviewed the third edition of this clear 
and correct text-book, a fact that proves, at all events, the success of 
the work. The present edition differs from its predecessors, not only 
