PORITES. i) 
but because at those points there are, or may be, trabecular thickenings of the tissue. The 
Diagrams B to H, fig. 3, which give some of the patterns assumed by the palic ring, show cases 
of single septa developing pali, while, again, other cases are seen (F, G, H) showing septa 
developing no pali, The difference in these cases seems to be due to the fact that these septa 
A B Cc 
Fic. 3.— Diagrams to illustrate some of the palic formule referred to in the descriptions of the 
forms. A is an ideal calicle, showing twelve septa, with primary and secondary cycles. 
This (see text, pp. 18, 20) is, however, probably never seen in Porites, the appearances 
suggesting it being secondary, and due to the fact that the intra-calicular trabecule do 
not grow as fast as the wall trabeculz, and the calicle is consequently deep. In E septal 
granules are indicated to show how it is possible for them to take part in the formation 
of the palic ring, which they sometimes seem to do. In G we see the trident formation 
mentioned here and there in the descriptions, the ventral directive being joined by a radial 
strand to the central tubercle and to the two lateral septal granules by synapticule. 
do not yet project far enough, the trabecule of their inner edges having lagged behind and not 
risen to the surface, while in B, C, D the inner trabecule of the same septa rise up as pali to 
D 2 
