61 
The surface of a corallum, representing its absolutely final period of 
growth, has not been observed, but the outline was certainly undulating, and 
was in all probability covered Avitb “ monticules.” The present surface (PL 
II, Pig. 1) of a fine radiating mass most distinctly shows these (PL 5, Pig.l), 
and it is not improbable that this character led Prof. P. M‘Coy to describe S. 
crinita as with a “ mammillated surface like that of the Ceriopora verrucosa 
Goldf.).”') 
The monticules measure, as a rule, about two lines in diameter, and arc 
separated from one another by the same distance, or even three lines. The 
corallitcs composing them do not appear to materially differ from the others 
in size. It may be that the groups of corallites of smaller size, described by 
Prof. Nicholson and the Writer as seen at tolerably regular intervals in 
sections, may be those corresponding to the monticules at the surface. 
The growth of the corallum was periodic, even from its youngest 
stages (PL III, Pig. 1). Indeed, this appears to be a cbaracter incidental to 
the whole group of Stenoporce, but is particularly characteristic of this 
species. The entire corallnm is stratified in layers of very regular thickness 
(PL II, Pigs. 1 and 2), a feature excellently shown in Lonsdale’s original 
figure,^ and referred to by Dana in tbe following words : — “ They ” (i. e., the 
corallites) “ separate rather easily, and are singularly regular in form, with 
few constrictions from irregular growth, and these commonly very slight, and 
in concentric lines, which sometimes give a specimen the appearance of being 
made of successive tiers of columns.”^ 
The strata in S. crinita vary from three to ton millimetres in height, 
and so marked a feature is this stratification that, unless great care be taken, 
specimens in the slightest degree weathered break up along these planes. 
It is possible in certain states of preservation to peel off the strata, corallite 
by corallite, leaving an entirely new surface exposed after eaeh operation. 
Stenopora crinita was, in all probability, attached by the whole of the base 
(PL III, Pigs, land 2), that is to say, the object which any individual particularly 
favoured was entirely coated or surrounded by it. The specimen represented 
in PL III, Pig. 1, has selected a Strehlopteria, and has spread out from that 
in a concentrically circular manner. Stratum upon stratum, until a base has 
been produced differing little in general a 2 )pearance from some Pavositoid 
corals. Other s}:)ec linens in the Colleetion have attached themselves to 
univalve shells, and completely invested them. 
^ Ann. Mag. Nat. Hist., 1847, XX, p. 22C. 
* Strzelecki's Pliys. Descrip. N. S. Wales, &c., 184.'), t. 8, f. 5. 
3 Wilkes’ U. S. E.xplor. Exped., 1849, Vol. X (Geology), p. 711. 
