PART II. 



SYSTEMATIC. 



CLASSIFICATION OF THE MADREPORARIA. 



The absence of any extensive knowledge of the morphology of the polyps of the Madreporaria 

 accounts, in some measure, for the anomaly that the classifications of the group proposed from 

 time to time have been founded upon skeletal characters alone. The best known, and until 

 recently most widely accepted arrangement, is that presented by Milne Edwards and Haime, 

 in their Histoire Naturelle des Coralliaires (1*57-1860). These writers divide the Sclero- 

 dermic Zoantharia, upon skeletal considerations only, into live sections: Madreporaria aporosa, 

 Jf. /'• rforata, M. tubulosa, M. tabulata, and M. rugosa. According- to Professor Duncan, in 

 Revision of the Families and Genera of the Madreporaria (1885), the Tubulosa no longer exists, 

 and the section Tabulata has been eliminated by H. N. Moseley." Duncan, however, accepts 

 the Madreporaria Aporosa, Perforata, and the Rugosa. ,1. .1. Quelch, in the report on the 

 "Challenger" reef corals (1886), altogether rejects the ancient group of the Rugosa, and mingles 

 its families with those of the more modern Aporosa.'' 



Mainly upon considerations of the presence or absence of a Randplatte or Edge-zone, von 

 Heider (1886) has suggested the possibility of subdividing the Madreporaria into Euthecalia 

 and P» udotheealia; A. Ortmann (1890), from his studies of the thecal characters and methods of 

 asexual growth, recognizes the two orders Athecalia and Euthecalia, and subdivides the first into 

 three suborders: Tnexpleta, Synapticulata, and Pseudothecalia. The latest important attempt at 

 founding a taxonomic system, based entirely upon skeletal characters, is the arrangement 

 proposed by Miss Ogilvie (1897), as a result of her elaborate investigations on the microscopic 

 structure of the corallum. 



While acknowledging the value of many of Miss Ogilvie\s suggestions, the classification 

 advanced lias everywhere been received with hesitation. In his recent paper on the corals 

 of the Gulf of Lyons. Professor Lacaze-Duthiers (1897) contends for the retention of the 

 classification of Milne Edwards and Haime as entirely adequate for all practical purposes. 



In the present connection it is not proposed to discuss all these suggested schemes. It is 

 generally admitted that the skeleton alone is inadequate as a basis upon which to establish a 

 natural classification. It is only needful here to refer to whatever attempts have been made to 

 utilize the anatomical characters of the polyp. In general, the skeleton of corals so very closely 

 reproduce- the fundamental characteristics of the polyps themselves, that an approximate 

 knowledge of the essential features of the latter can often be surmised from it, much more than 

 in the case of the skeleton and soft parts of the more complex groups of animals. Thus, the 



"see also Yerril], 1869, p. 518. 



6 Bourne, in the article " Anthozoa", in Lankester's Treatise on Zoology, adopts the classification of Duncan, 

 with the modifications introduced by Quelch. In doing so, he writes i p. Til) : " It cannot lie pretended that it is a 

 natural or a satisfactory classification, yet it is the best which can be offered in the present state . if mir knowledge. 



Other systems have been proposed, but they have not st 1 the test of criticism, and have been ephemeral." 



535 



