Prof. H. A. Nicholson—On Syringolites, Roemeria, etc. 435 
(1) The corallites in Roemeria are enormously thickened by a 
secondary deposit of stereoplasma; whereas those of Syringolites are 
thin-walled, and resemble those of Favosites proper. 
(2) The mural pores of Roemeria are of large size, are few in 
number, and are irregularly distributed; whereas those of Syringo- 
lites resemble the pores of Favosites proper in being of small size, 
numerous, and regularly distributed. 
Fic. 2.—Transverse section of Roemeria minor, Schliiter, from the Middle Devonian 
rocks of Dahlem, in the Eifel, enlarged about six times. p. Mural pore. 
Fic. 3.—Vertical section of Roemeria minor, Schliiter, from the same locality, 
similarly enlarged. pp. Mural pores. \ 
(3) The septal system in Roemeria is rudimentary or absent ; 
whereas in Syringolites each corallite is provided with well developed 
septal ridges, the number of these structures in each tube appearing 
