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CHAPTER V. 



THE SUBDIVISIONS OF MONTICULIPORA. 



From a theoretical and strictly scientific point of view, the 

 family of the Montic2tliporidcu must be regarded as comprising 

 only the single genus MontiaLtipora, D'Orb. That is to say, 

 our present knowledge does not appear to be sufficient for the 

 establishment of any subdivisions within the limits of this com- 

 prehensive genus, which are so markedly distinguished by 

 their structural characters that they would take rank as natural 

 and undoubted genera. Hence I have formerly divided the 

 genus ]\Ionticulipora into the six sub-generic groups, Fistiili- 

 pora, M'Coy, Constellaria, Dana, Dekayia, Edw. and H., Diplo- 

 trypa, Nich., Heterotrypa, Nich., and Monotrypa, Nich. (Pal. 

 Tab. Cor., p. 291). While the above-mentioned six groups 

 are so closely allied to one another that there is no difficulty in 

 framing a generic diagnosis which will embrace them all, the 

 first three of these — viz., Fistulipora,WQ.oy, Constellaria, Dana, 

 and Dekayia, Edw. and H. — possess certain marked structural 

 features by which they can be readily separated from one 

 another, often by a merely superficial examination. Upon 

 the whole, therefore, it may perhaps be the best plan, as a 

 matter of practical convenience, to regard these three groups as 

 so many distinct ^^7/cr^, in spite of the fact that they have no 

 theoretic claim to such a rank. The adoption of this method 

 of procedure will leave JMonticnIipora proper as an independent 

 genus, with the three subordinate groups, Diplotrypa, Hetero- 

 trypa, and Monotrvpa, to wliich must be added as a fourth sub- 



