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SOME NEW BOOKS. 



The British Museum Catalogue of Madrepores. 



Catalogue of the Madreporarian Corals in the British Museum (Natural 

 History). Vol. ii. The genus Turbinaria. The genus Astraeopora. By Henry 

 M. Bernard. Pp. iv., io6, plates xxxiii. Published by order of the Trustees. 

 London, 1896. Price i8s. 



Following upon the late Mr. George Brook's monographic catalogue 

 of the genus Madrepora, comes the present volume, dealing with two 

 genera of perforate corals, together including a far smaller number of 

 species than the single genus Madrepora. Mr. Bernard has proved a 

 worthy successor to Mr. Brook, and in compiling this catalogue has 

 followed with tolerable closeness the lines laid down by his 

 predecessor. The diagnoses of both genera and species have been 

 framed with evident care, while the illustrations are numerous and 

 very good of their kind. The collotype reproductions of photographs, 

 introduced with such success by Mr. Brook, have been used in 

 illustration of the entire specimens and show the habit of the colonies 

 very well. Mr. Bernard, however, has improved upon the method of 

 his predecessor, by introducing a number of lithographs showing 

 details of corallites : these drawings, which illustrate the characters 

 used to diagnose the different species, are of great value, as may well 

 be understood by anybody who has attempted to determine the species. 

 of a coral from verbal diagnoses alone. 



Every student of corals knows that they are protean in their 

 variety, and that there may often be found, on one and the same 

 colony, calicles of diverse and perplexing forms. This difficulty is 

 emphasized by Mr. Bernard, who gives an account of the variations 

 of each component of a calicle, and shows that there is no single 

 character to be relied upon as a sure mark of specific distinctness. 

 Finally, he complains of the restraint of the Linnean system, and 

 prophesies a time when we shall have recourse to some other 

 conception than that of a species. Such a complaint is scarcely in 

 keeping with the progress of our ideas, for there are few nowadays 

 who regard a species as necessarily fixed and invariable, or as varying 

 only within very narrow limits. All Anthozoa present the most 

 perplexing gradations of character, and the Zoantharia do not afford 

 the same easy means of identification as do the Alcyonaria, for there 

 are no spicules of characteristic and constant form. In point of fact, 

 Mr. Bernard has in his arrangement expressed very well the modern 

 conception of a species. He has selected certain leading features (in 

 this case the habit of growth is most relied upon), and he has arranged 

 his collection in groups about selected individual specimens chosen as 

 types. Each group constitutes a species. The species, as thus 

 arranged, will have a greater or less value according to the skill with 

 which the author chooses his type-specimens, and his instinctive 

 aptitude for associating with them those forms which most truly 

 resemble them. By " most truly " we mean in the greatest number 

 of particulars. 



