64 
are either straight, or slightly curved, retaining the same diameter for some 
distance, or expanding slowly upwards; in this condition of the corallum 
the resemblance to such corals as Cyathophyllum giganteum, Mich., is very 
marked; by copious budding large bunches of corallites are formed. The 
turbinate outline is seen in the earlier stages of each corallite in T. wellington- 
ensis, then passing into a more irregularly cylindrical condition, often twisted, 
or even slightly contorted. In T. princeps the base is pointed, but in the 
previous form it may be in the same condition, or somewhat expanded ; in 
both the section is circular or oval, the diameter of T. princeps attaining two 
and a half inches, but that of its fellow is far less. The corallites of the 
former vary in length, but are known to extend to eleven inches, those of 
T. wellingtonensis being comparatively short at first, but by repeated 
gemmation forming a line of individuals four inches, and probably more, in 
length. Ob-conical to cylindrical corallites also characterise T. derrengul- 
lencnsis, and may become twisted or contorted ; this species bears the dis- 
tinction of presenting the greatest outward resemblance to T. ( Pholidophyllum ) 
tubulatum. 
In T. liliiformis the corallites are liliaceous in outline — i.e., there is 
a stalk or stem-like portion below, resembling a non-budded corallite of 
T. dendroidea, varying much in length, and expanding above into wide 
bell-mouthed calices, as much as three inches in diameter. As a rule these 
corallites are erect, but are sometimes diverted to one side or the other, 
although not contorted. 
3. Wall . — In all these corals the wall proper must have been thin and 
delicate. More often than not fossilisation has removed it, but when present 
the wall is always represented by a thin, dark circle supported inwardly by a 
zone of secondary deposit of variable thickness. In some instances the bases 
of the septal lamellae are distinctly traceable to this thin theca, and it may, 
in consequence, be justly concluded that this latter is formed by the confluent 
bases of the septal lamellae. 
4. j Epitheca . — I am hut imperfectly acquainted with the nature of 
this investment ; it is seldom preserved, and if so, only indifferently. So far as 
one can see, it consisted of a thin layer of tissue concentrically lined, the 
strength and distance apart of the threads varying according to species. 
This epithecal layer also clothed the radiciform processes and fistulae. 
5. Exotliecal Scales . — No trace whatever of these much debated scales, 
first noticed by Lindstrom, and compared by him to the opercula of Primnoa , 
