Prof. H. A. Nicholson—On Syringolites, Roemeria, etc. 437 
not a vital one, since in C. Labechet the tubes have commonly the 
compressed form and alternating arrangement which is characteristic 
of the typical forms of Alveolites. Again, little importance can be 
attached to the mode of distribution of the mural pores, since in 
C. Labechei these structures seem to be confined to the short 
ends of the compressed corallites, whereas in C. Battersbyi they are 
asserted by Schliiter to occur indifferently- on all the faces of the 
corallites. Of still less importance is the supposed absence of 
tabule, since this rests upon a misconception. Not only are 
tabule largely present in C. Labechei, but, in all the specimens of 
C. Battersbyi which I have examined, I have found these structures 
to be fairly well developed, though they are often comparatively 
few in number (Fig. 4,8). Some of the tabula of C. Battersbyt 
have the ordinary form of complete transverse plates; but this 
species is furnished in addition with numerous imperfect, cup-like 
tabulee, which project but a short way into the visceral chamber 
of the corallites, and which have been compared by Professor 
Schliiter with swallows’-nests attached to the wall of a house. In 
C. Labechei all the tabula seem to be complete, and there are none 
of the peculiar incomplete or squamous tabulee which occur in 
C. Battersbyi. 
Fic. 5.—A. Transverse section of Caliapora Labechei, K. & H., sp. enlarged six 
times. B. Vertical section of the same, similarly enlarged. From the Wenlock 
Limestone of Much Wenlock. 
The most characteristic feature of the genus Caliapora, as com- 
pared with Alveolites, is to be found in the fact that the corallites are 
provided with numerous strong ascending tooth-like processes, 
which must be regarded as of the nature of septa (Figs. 4 and 5). 
The existence of these strong tooth-like spines in Caliapora Bat- 
tersbyi is recognized by Schliiter, but they are regarded as being due 
to the intersection of the cup-like squamous tabulz above spoken of. 
In this view of their nature I am unable to agree, and I regard them 
as structures having an independent existence. This is clearly the 
case in C. Labechei (Fig. 5), where their septal nature is quite in- 
disputable. If this view be correct, then the essential feature which 
distinguishes Caliapora from Alwveolites is the possession by thie 
former of strong tooth-like septal spines, which are developed in 
