VERMES, CCELENTERA AND PROTOZOA. 



ALTHOUGH there are no very startling discoveries 

 to record either in the anatomy or development of 

 the lower groups of Invertebrates, we may consider that, 

 on the whole, very steady progress has been made. 



Those investigators who devote their energies to these 

 lowly creatures have been filling up the gaps in our know- 

 ledge of the anatomy and development of some of the 

 most important and interesting genera, or in completing, 

 so far as possible, the account of their distribution over 

 the face of the globe. Several new genera and species 

 have been described, the number being considerably larger 

 in the groups of parasitic worms and protozoa than in the 

 Ccelentera, but no new forms of any very striking morpho- 

 logical importance have come to light ; nor have any con- 

 siderations, based upon anatomical or embryological research, 

 been brought forward, which would justify any serious 

 alterations in the classifications that are usually adopted. 



The most important monograph dealing with special 

 genera is that of the late George Brook, on the genus 

 Madrepora, published by the trustees of the British 

 Museum. This valuable work contains an account of no 

 less than 220 species, and is fully illustrated by 35 quarto 

 plates of collotype reproductions of photographs taken by 

 the author. 



A careful and conscientious monograph such as this is 

 cannot fail to be of great use to those who wish to identify 

 species ; but it is greatly to be regretted that the author's 

 life was not spared to give us a condensed summary of the 

 known facts concerning the geographical and bathymetrical 

 distribution of the genus. 



Before the publication of Brook's monograph, Rehberg 

 had published 1 some useful lists of the names of the species 

 of Madrepora occurring on the coral reefs of different regions 



1 Rehberg, H., Neue und wenig bekannte Korallen, Abh. Ver. Hamb., 

 xii., pp. 1-50. 



