1900.] Starfishes and their Relations. 119 



The first instalment of Professor Lankester's Treatise on Zoology has 

 now appeared. It is not one of that class of works just referred to. On 

 the contrary an attempt is made to mention every known genus, 

 whether recent or fossil. The general aim of the work is to give a 

 systemetic exposition of the characters of the classes and orders of the 

 animal kingdom, but it is intended rather to assist th e student who has 

 already acquired a preliminary knowledge of zoology and who wishes to 

 proceed to a more thorough study of the subject. The volume just 

 issued has an introductory chapter containing a general description of 

 the sub-kingdom or phylum Echiuoderma (sea-urchins, starfish, &c.); 

 then follow chapters on the various classes, viz. : Cystidea, Blastoidea, 

 Crinoidea, Edrioasteroidea, Holothuroidea, Stelleroidea, and Bchinoidea. 

 One of the principal merits of this treatise is that the extinct groups of 

 animals are dealt with quite as fully as the recent ones. The idea of 

 giving a continuous detailed history in which the evolution of a series of 

 forms may be traced from the earliest Palaeozoic periods up to the 

 present day is an excellent one, and no book attempting such a task in 

 so comprehensive a manner has ever been written. 



The present volume contains a vast amount of information, j-et it is 

 inevitable that the various groups of Echinoderma should have been 

 treated somewhat unequally. It is perhaps not in the scope of the 

 work to enlarge too much upon the habits and the mode of life of the 

 animals referred to, still it seems strange that scarcely any special 

 mention is made of these particulars in the case of the Crinoidea 

 and Stelleroidea, whilst as regards the Echinoidea we get a brief 

 description at least of their mode of life. 



The announcement by the Editor that the treatment of the subject 

 must necessarily be brief, as the treatise will have to be completed in ten 

 volumes, will give the student some idea of the magnitude of the subject 

 and of the advances which have been made in recent years. Professor 

 I^ankester is assisted in his great undertaking by a number of experts — 

 mostly graduates of the University of Oxford, who have promised to 

 contribute portions of the work. The names selected are a sufficient 

 guarantee that the volumes when completed will be thoroughly reliable 

 and satisfactory. 



A most useful bibliography of the groups described is given at the end 

 of every chapter. The index at the end of the volume might with ad- 

 vantage be enlarged, so as to include the family names, which have been 

 left out, and increase the number of cross-references. 



The book is excellently printed and illustrated by a large number — 

 about 300 -of clear and useful figures, most of which are original. This 

 great work will be indispensible to all teachers and advanced students 

 of zoology, and especially to curators of natural history museums, and 

 it is to be hoped that the remaining volumes may soon be published. 



R. F, S. 



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