M r . J . D . D ana on Zoophytes . 101 



From this table, it appears that only twenty-seven species ont 

 of 306 are known to be common to the East Indies and Pacific 

 Ocean. With regard to those common to the East and West 

 Indies, for which no column is assigned, there are but two, — the 

 Meandrina labyrinthica and Astrea galaxea, — about which much 

 doubt remains. 



We have no authority for accrediting to the W r est Indies any 

 species of the genera Fungia, Pavonia, Herpetolithus, Merulina, 

 Monticularia, Gemmipora, Anthophyllum* , Pocillopora, Sidero- 

 pora or Seriatopora, all of which are common in the opposite 

 hemisphere. The Agaricia, with the exception of two osculant 

 species, are confined to the subgenus Mycedia, exclusively West 

 Indian, which contains very firm compact corals, often with an 

 Astraa-like character. The Millepores are the only known Fa- 

 vositida, and but half a dozen Madrepores have yet been distin- 

 guished. The Manicina, Caryophyllice and Oculince are more 

 numerous in the West Indies than elsewhere, and the Cteno- 

 phyllicB [Meandrina with stout entire lamellae) have been found 

 only in the West Indies. The genus Porites contains several 

 species, but they are uniformly more fragile and more porous 

 species than those I have seen from the Pacific and Indian 

 Oceans ; and the polyps, as figured by Lesueur, are more exser- 

 tile, approaching in this particular the Gonioporce. 



General Remarks on Classification. — It has often been justly 

 said, that there can be but one strictly natural classification in 

 either of the organic kingdoms. Yet if we look upon any system 

 presented in the usual order on paper, as correctly and completely 

 the natural system, we greatly mistake nature ; for the various 

 affinities cannot be fully expressed on a plane surface. The lines 

 are so many, and so interlaced, that to be understood, they must 

 be conceived of as ramifying in space. The mind, proceeding 

 properly to its work, determines first upon those qualities which 

 are physiologically of the most fundamental importance : it fol- 

 lows out the variations of structure under the grand divisions 

 thus ascertained, fixing its attention successively upon qualities 

 of a less and less general character ; it traces the species through 

 the various modifications in these several particulars, marking out 

 the lines of gradation in affinities, — observing, some it may be, 



at bottom {Porites clavaria and the allied). The other Porites, with a few 

 exceptions, belong to the genus Manopora of the author, and are true Madre- 

 pores in their cells, but with imperfect calicles or none: the P. spumosa of 

 Lamarck, and the allied, are here included, besides the Montipora of Blain- 

 ville. 



* Sarcinula in part of Blainville, Caryophyllia in part of Lamarck ; An- 

 thophyllum of Schweigger, who introduces the name, but not of writers on 

 fossil corals. 



