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BIBLIOGRAPHICAL NOTICE. 



A Manual of the SubJcingdom Coelenterata. By Joseph Reay 

 Greene, B.A., Professor of Natural History in Queen's College, 

 Cork. Loudon, 1861. Longmans. 12mo. 



After an interval of about two years, we have to notice the appear- 

 ance of the second of Messrs. Galbraith and Haughton's series of 

 scientific manuals ; and it is not too much to say that in the execu- 

 tion of the present little work Professor Greene has fully equalled, 

 if not surpassed, his former effort. The length of time that has 

 elapsed between the publication of the two manuals is perhaps to be 

 regretted ; but our knowledge of the interesting animals now com- 

 monly known as Coelenterata is in such a progressive state, and even 

 the literature of the subject requires such careful study to enable 

 one to see one's way at all clearly through the obscure labyrinth of 

 errors, misconceptions, and confusions of all kinds, gradually set up 

 by different authors, that we can hardly wonder that Professor Greene 

 has found it impossible to get through his task with less delay. It 

 is evident, indeed, throughout the work, that it is the result of a 

 patient and conscientious study, both of the literature of the subject 

 and of the animals themselves ; and as Professor Greene belongs to 

 the most advanced school of zoologists, we have in the present 

 manual an excellent epitome of the views of that school upon the 

 second great division of the animal kingdom. 



Of the necessity for the establishment of a distinct group for the 

 gelatinous Ptadiata of Cuvier there can hardly be two opinions, 

 although, perhaps, there may be some doubt amongst naturalists as 

 to the position to be assigned to the Echiuodermata. The difficulty, 

 however, is not to be got over by ignoring, as has been done recently 

 in some cases, the great divisions or subkingdoms altogether, and 

 treating classes as the highest groups in the animal kingdom. This 

 is simply shirking the question ; and it has the great disadvantage 

 of obscuring or altogether throwing out of sight many of those in- 

 teresting points of morphology which it has been the object of the 

 researches of some of our leading naturahsts to bring to light. This 

 view is evidently that of Professor Greene, who regards the Polypes 

 and Acalephs of Cuvier as constituting a primary division of the 

 animal kingdom, distinguished by " a plan of structure, or relative 

 position of parts, peculiar to itself," for which he adopts Leuckart's 

 name of Coelenterata. 



The members of this group are divided by our author into two 

 great classes, the Hydrozoa and Actinozoa, — the former including 

 the Hydroid polypes and tlie greater part of the Acalephs ; the latter 

 the Helianthoid and Asteroid polypes, with the Ctenophora, which 

 are removed from their previous association with the Acalephs. 

 This is the greatest departure from the old system to be found in 

 Professor Greene's classification ; and although it may at first sight 

 seem like a violation of old-established relations, it appears to us 

 that the elimination of the Ctenophora is necessary to give homo- 

 geneity to the class Hydrozoa. Whether they ought to be placed 



