37 



CHAPTER III. 



GENERA OF FAVOSITID^E. 



Genus FAVOSITES, Lamarck, 1816. 

 (Hist, des An. sans Vert, vol. ii. p. 204.) 



Calamopora, Goldfuss, Petref. Germ., vol. i. p. 77, 1826. 



Emmonsia, Milne-Edwards and Haime, Pol. Foss. des Terr. Pal., p. 246, 1851. 



Astrocerium, Hall, Pal. N.Y., vol. ii. p. 120, 1851. 



Gen. Char. Corallum massive or branched, composed of nu- 

 merous more or less conspicuously polygonal corallites, which 

 are in close contact with one another, but are not amalga- 

 mated by their walls. Walls lamellar, perforated with one 

 or more rows of circular " mural pores," by which the separate 

 corallites are placed in communication. Visceral chamber in- 

 tersected by a greater or less number of complete or incom- 

 plete transverse partitions or " tabulae." Septa obsolete, or 

 represented by vertical rows of tubercles or pointed spines. 



The general form of the corallum in this genus is very vari- 

 able, but the most typical species (e.g., F. Gothlandica, Lam.) 

 possess a discoidal, hemispherical, or subglobular skeleton, of a 

 massive character, and often attaining very considerable dimen- 

 sions. Other forms, again, have the habit of growing in cylin- 

 drical or flattened ramose expansions ; but most of the so-called 

 " dendroid " species of Favosites may be placed under allied 

 generic types. The forms with a discoidal or expanded, and 



