Manchester Meuioirs, Voi. liv. (1910), No. \%. 3 



luin show that fusions of an irregular character between 

 protosepta and prntosepta, and between protosepta and 

 columella, occur throughout the corallum from the 

 plane of first fusion as far down as the upper part of 

 the inflated base. In using the expression "irregular," it 

 is only intended to signify that at present the order of 

 the fusions, if there is an order, has not been determined. 

 The general appearance of the contents of the lower part 

 of the corallum is that which is sometimes called vesicular 

 tissue, or " endotheca," so characteristic of the fossil corals 

 of the family Cyathophyllidae. 



Fig, I. 



Fig. 2. 



Fig 



Figs. 1-3. — Diagrammatic sketches of the septal arrangement of 

 PyrophyUia injlata. c columella, iii.s. metasepta, p.s. protosepta. 

 Fig. I. — Arrangement of the septa just below the margin of the 

 calyx ; Fig. 2, at the base of the calyx ; Fig. 3, in the lower parts of 

 the coral. 



The septa, although sinuous in their course, are 

 smooth and without perforations, granulations, or synap- 

 ticulae. 



In the lower part of the calyx the columella unites 

 with the protosepta. In some sections taken near the 

 base all the eight protosepta are fused with the columella 

 {^Fig. 3), but between that region and the upper or calical 

 end sections show a very irregular fusion of columella 

 with protosepta {^Fig. 2). There is no reason for believing 

 that, as in Guynia, the columella fuses with one locally 



