38 



VERRILL ON THE POLYPS OF THE 



Leaving Turbinolidce out of consideration for the present, the Astbjeabia may be arranged 

 as follows : — 



A. Fissiparous Astr^earia, embracing three families. 



I. Eusmilince M.-Edw. and H., having the edges of the septa entire, without paliform 

 lobes ; polyps with the disk in expansion raised above the coral ; tentacles well developed, 

 cylindro-conical. 



II. Lithophyllince, corresponding to a part of Lithophylliaceoi M.-Edw. These have the 

 edges of the septa divided into strong teeth or spines, without paliform lobes ; disk level 

 with the top of the cells ; tentacles surmounting the top of the septa, short, conical, 

 numerous {Mima, Isophyllia, etc.). 



III. Mceandrince, including part of LithophyttiacecB M.-Edw., viz. : Mceandrina, Manicina, Hydno- 

 phora, TridacophyJMa, Colpophyllia, etc., together with Faviacece. In these the septa have 

 their edges finely toothed or crenulate, with a paliform lobe towards the base. The small 

 tentacles are placed at the top of this paliform lobe, and the disk extends across the cells 

 even with the top of the paliform lobes, and does not rise level with the summit of the 

 walls. 1 



B. Gemmiparous Astr^earia, containing four families. 



IV. Siylinince, corresponding with Stylinacece M.-Edw. and Haime. Septa with entire 

 edges ; dissepiments well developed ; coenenchyma absent. 



V. Astrceinm, embracing only a part of the same group as limited by Milne-Edwards and 

 Haime, viz : Astrcvacece. [pars), Cladocoracece, Astrangiaccce. These have dentate septa, rudi- 

 mentary coenenchyma, dissepiments usually well developed. 



VI. Stylophorinoi M.-Edw. and H., including Stylophora, Madracis, etc. In these there is 

 a well-developed coenenchyma, uniting the polyps, which is most compact at the surface. 

 The cells have a tendency to fill up at the surface and remain more open below. Septa 

 mostly entire. 



VII. Octdinidce, corresponding to the same group of Milne-Edwards and Haime, with the 

 addition of Didichopora and, perhaps, Errina. The cells have a tendency to fill up com- 

 pletely from below by deposition of solid matter ; dissepiments not very well marked ; 

 coenenchyma well developed, compact. 



Of these only the fifth and last are represented within our limits, so far as now known ; 

 yet species of all the others, except Stylinince, occur about the Florida Reefs. 



Family Astr^ein^e Milne-Edwards. 



We have restricted this name, as indicated above, to but a small part of the forms in- 

 cluded by Milne-Edwards and Haime. This has been done principally from a consideration 

 of the structure of the soft parts. In this respect this group differs widely from most other 

 Astrazidce, agreeing more nearly with Oculina than with any other division that I have had 

 an opportunity to examine. The upper portion of the polyp has the power of rising out 



1 This peculiar character, which separates Mceandrince alcohol, and with the figures of the living polyps of Mussa 



from Lithophyllince, I have ascertained from numerous ex- and Symphyllia in Dana's Zoophytes. The polyps of Mce- 



aminations and dissections at the Museum of Compara- andrina have also been well figured by LeSueur, Dana, 



tive Zoology of alcoholic specimens of Mceandrina, Manx- and others. 

 cina, and Favia, compared with Isophyllia dipsacea, also in 



