74 
It is, however, in T. princeps that gemmation is seen in its most 
vigorous aspect. A series of buds, in one case as many as thirteen 
(PL XIX, fig. 2) arise around the inner edge of the calice of the completed 
single corallum, and in their turn become well-developed corals, forming a 
proliferous sub-compound cluster. A similar form of increase is met with 
in T. ( Ccelophyllum ) eury calyx, Weissm. 1 2 Even in so small a form as T. 
clerreng ullenensis four buds are attached to one calice ; budding seems to 
have commenced at a very early stage in this species. 
In T. vermiformis there are two or four buds, which curve outwardly 
from the parent. In the case of four, reproduction is exactly similar to that 
of Whiteaves’ Pycnoslylus guelpkensis , z four equal buds usually occupying 
the whole of the interior of the parent calice, and each deltoid-triangular in 
sectional outline ; this resemblance is verv remarkable. Increase in T. 
dendroidea is by two to four large vigorous buds, which soon diverge from 
the parent stem (PI. XIV, fig. 1 ; PI. XV, fig. 5). 
In a remarkably interesting paper “ On the Mode of Growth and 
Increase amongst the Corals of the Palceozoic Period,” 3 the late Prof. H. A. 
Nicholson subdivided gemmation, or increase, under five heads, viz. : — 
1. Simple calicular gemmation. 
2. Compound calicular gemmation. 
3. Parietal or lateral gemmation. 
4. Basal gemmation. 
5. Eission. 
Gemmation in the Australian Try plasma is confined to Sections 1 and 
2, and possibly 3, and the species group themselves as follows : — 
Section 1. — T. wellingtonen&is and possibly T. (?) Murrayi. 
Section 2. — The remainder, with the exception of T. delicatula and 
T. columnaris, in which the budding is unknown. 
Ur. Lindstrom drew attention to a very interesting point in the growth 
of new calices within the old ones in the Zoantharia Rugosa, 4 and which is 
not, strictly speaking, true ealicinal budding. lie instanced a specimen of 
Goniophyllum pyramidale, Ilis., in which a new coral was formed within the 
calice of an older individual, and partly so of the old walls of the latter. 
1 Weissermel — Zeitssch. Deuts. Geol. Gesellscli., 1894, XLVI, Heft 3, p. 036, f. 1 and 2. 
2 Whiteaves — -Canadian Pal. Foss., 1884, II, Pt. 1, t. 1, f. 1& ; Lambe — Contrib. Canadian Pal., 1901, IV, 
Pt. 2, t. 10, f. 4, 4a. 
3 Nicholson — Trans. R. Soc. Edinb., XXIV, pp. 237-24.3. 
* Lindstrom — Geol. Mag., 1866, III, p. 300. 
