434 Prof. H. A. Nicholson—On Syringolites, Roemeria, etc. 
thin-walled, closely contiguous, and furnished with one or more 
rows of small mural pores on each prismatic face. The corallites 
are intersected by numerous annular tabule, which are invaginated 
centrally so as to give rise to a median cylindrical tube, which 
occupies the centre of each visceral chamber, and is furnished with 
imperforate walls. The upper surfaces of the tabule show well- 
marked septal ridges (primarily twelve in number), which are 
covered with minute tubercles or spines, two to four rows of such 
tubercles apparently corresponding with a single septal fold. 
Increase of the corallum takes place by intercalicinal gemmation. 
The essential characters of Syringolites Huronensis, as above briefly 
described, are that the prismatic corallites are thin-walled, and are 
furnished with numerous regularly-distributed mural pores, while 
the septal system is fairly represented by radiating tuberculated 
ridges, which are primarily twelve in number in each corallite. 
The only corals which have been recognized as belonging to the 
genus Roemeria, H. & H., are the R. (Calamopora) infundibulifera 
of Goldfuss, and the R. minor of Schltiter, both of which occur in 
the Middle Devonian of Germany. I have had the opportunity of 
examining the original specimens of the former of these, which are 
preserved in the University Museum in Bonn; but, so far as ] am 
aware, no complete microscopic examination of these has ever been 
carried out. There is, however, no doubt that R. minor, Schliiter, is 
congeneric with RB. infundibulifera, Goldf., and through the kindness 
of Professor Schliiter, I have been enabled to make a thorough 
microscopic investigation of the former, which I shall therefore take 
as the type of the genus Roemeria. 
The corallum in Roemeria minor forms small flattened expansions, 
composed of erect, polygonal, and contiguous corallites. Thin 
sections, both transverse and longitudinal (Figs. 2 and 38), show that 
the corallites are bounded by a thin and well-developed primor- 
dial wall, which is enormously thickened by a dense deposit of 
secondary sclerenchyma (‘stereoplasma”), the visceral chamber 
being thus greatly constricted. The visceral chamber of the 
corallites, thus restricted, is traversed by a succession of infundi- 
buliform tabulae, which are invaginated one into another, but can 
hardly be said to give rise to a definite median tube. The septa are 
practically undeveloped, though one may occasionally observe blunt 
vertical ridges, which are possibly of a septal nature. The mural 
pores are of very large size, and comparatively few in number, and 
are quite irregular in their distribution; while owing to the enor- 
mous thickening of the walls of the corallites, they present them- 
selves as elongated canals joining the visceral chambers of contiguous 
tubes. Increase of the corallum takes place by means of intermural 
gemmation. 
From the above short description of the structure of Roemeria 
minor, as illustrated by the accompanying figures of thin transverse 
and vertical sections, it will be obvious that Syringolites, Hinde, differs 
in characters of fundamental importance from Roemeria, H. & H. 
This will be sufficiently evident from the following summary : 
