I02 TABULATE CORALS. 



Genus Trachypora, Edwards and Halme, 1851. 

 (Pol. Foss. des Terr. Pal., p. 305.) 



Gen. Char. — Corallum dendroid, of compact cylindrical stems, 

 attached basally to foreign bodies, and composed of conical 

 corallites which diverge with an increasing curvature from an 

 imaginary axial line to open on all parts of the free surface. 

 Corallites essentially polygonal, in close contact, their proper 

 walls usually not obliterated, and in no case separated by the 

 intervention of a true ccenenchyma. Interior of the tubes con- 

 tracted by the deposition of numerous concentric layers of scler- 

 enchyma, which increase in amount as the surface is approached. 

 Calices superficially widely distant from one another, arranged 

 in irregular longitudinal rows, the interspaces between them, 

 formed by their enormously-thickened lips, being ornamented 

 with grooves or ridges. Septa represented by radiately-placed 

 spines or tubercles, or obsolete. Tabulae few, remote, com- 

 plete. Mural pores generally well marked, but few and 

 irregular. 



Obs. — The genus Trachypora was founded by Miine- 

 Edwards and Haime for the reception of the single species 

 T. Davidsoni, from the Devonian formation of France ; and 

 it was placed by these eminent zoophytologists {loc. cit) in 

 the family of the Seriatoporidce, in the immediate neighbour- 

 hood of Deiidropora, Mich., and Rhabdopora, E. and H., both 

 also founded upon single species. These three types, in fact, 

 if really capable of generic separation at all, are apparently 

 most closely allied to one another ; and as I do not possess 

 any specimens of the two latter, and as their microscopic 

 structure is wholly unknown, I shall make the few remarks 

 concerning them which may be necessary in connection with 

 the present genus, with the anatomy of which I am better 

 acquainted. 



My knowledge of the genus Trachypora is based upon a 

 minute examination of T. ornata, Rom., and T elegantula, 



