THE AVONIAN OP THE AVON GORGE 
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The rows of septal spine-bases are to be seen most clearly 
on the inside of tubes which have been split longitudinally 
and from which the tabulse have been removed by weathering. 
It was pointed out by Nicholson that Syringo'pora is a 
Favositoid genus in which the tubes are separated, and that, 
in consequence, the mural pores of Favosites are represented 
by the tubular connectors of Syringopora. Both genera 
possess the same type of septal structure. 
Figures: Ed. and H: Plate 46. 
Alveolites and Chcetetes. 
The only group with which we are here concerned is ‘ Alveo- 
lites ’ aff. se'ptosa. Nicholson has shown that this group is, 
probably, more correctly assigned to Chcetetes ; but, since the 
evidence is not conclusive, it seems preferable to retain the 
older and better-known designation. 
Corallum massive. 
Corallites : narrow, prismatic, contiguous tubes, probably 
unconnected by mural pores. 
Septa (?) none or, more usually, represented by one or more 
projections from the wall into the calyx. 
Tabulae horizontal and extending completely across the 
tubes. 
A horizontal section shows the closely-packed, 
adjacent polygonal cross-sections of the tubes, separated by 
thick undivided walls. A large number of the cross-sections 
exhibit one or more ‘ septal ’ projections. 
A vertical section shows the contiguous tubes com- 
pletely crossed by numerous thin horizontal tabulae and also 
exhibits the division of the whole corallum into thick con- 
centric layers. 
[The ultimate reference of this group to either Alveolites or 
Chcetetes must rest upon the following diagnostic characters : — 
Alveolites is a Favositoid genus, characterized by mural 
pores and by longitudinal rows of septal spines. 
