33° 



CHAPTER XIV. 



LABECHID/E. 



The extraordinary Upper Silurian genus Labechia, E. and H., 

 alone constitutes this group, and its characters are so abnormal 

 that we must in the meanwhile regard it as the type of a special 

 family, to which the name of LabechidcB may be applied. As 

 we have, however, to deal in this family with only a single 

 genus, comprising only a single species, the characters of the 

 group will be sufficiently elucidated by a consideration of the 

 structure of the genus. As a definition of the group it will be 

 sufficient to say that it comprises calcareous corals (?), composed 

 of laminar or submassive expansions, which are fixed by the 

 centre of the base, and have the rest of the lower surface 

 covered with an epitheca ; the skeleton being composed of a 

 series of calcareous, primitively tubular, but finally more or 

 less completely solid columns, which project above the surface 

 as so many rounded or elongated imperforate tubercles ; the 

 spaces between the columns filled with a cellular tissue of len- 

 ticular vesicles, and the intervals between the surface-tubercles 

 covered by a continuous and imperforate calcareous membrane. 



Genus Labechia, Edwards and Haime, 1851. 

 (Pol. Foss. des Terr. Pal., p. 279.) 



Gen. Char. — Corallum usually having the form of a larger 

 or smaller laminar expansion, which is attached by a portion of 

 its base to some foreign object, the remainder of the lower 



