128 NATURAL SCIENCE [August 



be found in his recent work in Gegenbaur's "-Festschrift." The 

 Turbinoliclae 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 thcca, 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 Steplianotrochus and others. Remembering that 

 the wall of Caryophyllia is a pseudotheca, it is difficult to place 

 FlabcUwm in the same group with it, and Miss Ogilvie's remarks on 

 Flabcllum 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 coralluin 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 

 suo'ii-ested 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 points 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 Bugosa. 



G. C. Bourne. 



B, Hertwig's Text-book of Zoology 



Lehrbuch der Zoologie. By Dr R. Hertwig. Fourth improved edition. 8vo. 

 Pp. xii. 612, with 568 text-figures. Jena: G. Fischer, 1S!>7. Trice 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 



