5G 
Primordial wall distinct, delicate, sometimes becoming thickened. Acantlio- 
jiores nsnally developed at the angles of j miction of the corallites, and when 
so few in number, of largo size, and forming blunt spines at the surface ; at 
times greatly develoj>ed in the thickened portions of the walls, when their 
situation is variable. Tabnhc complete, few, and remote, in the axial region ; 
becoming closer in the peripheral zone. 
Ohs . — The type specimen of S. ovata, like that of S. crinita, is pre- 
served in the Geological Department of tlie British Museum — that is to say, 
the sjiecimen which must be regarded as the type — for the original coral on 
which Lonsdale founded the name, and collected hy the late Dr. Charles 
Darwin, has lieon lost in the passage of time — is retained therein, and is that 
figured by Lonsdale in Strzelecki’s work. 
The corallum is dichotomoiisly branched, and must have attained 
some size, as the type measures four inches in length, and is clearly only a 
portion of a mucb larger example. Individual Ijranches retain their size 
throughout, very little diminution in diameter taking place towards their 
apices, and thus giving to the corallum a marked and probably specific 
appearance. Branches have been observed as small as a quarter of an incli, 
and as large as an inch in diameter, Avith the apices blunt and rounded, but 
examples Avith the axial region removed, leaving a hollow cylinder represented 
by tlie peripheral zone, have not come under notice, except from Tasmania. 
As might bo expected from its mode of groAvth, stratification, as a 
rule, does not take place in the axial region, nor to any extent in the 
outer zone, in our New South Wales siAecimens until the periphery is 
approached. The figured type does, it is perfectly true, as in all Tasmanian 
examples I liaAm seen, shoAV such demarcation in layers in the central zone. 
Nothing is knoAvn of the mode of attachment in this species, but 
judging from analogy, the base Avill jn-obably be found to be encrusting rather 
than enveloping. 
The persistent manner in Avhich the matrix invariably adheres has 
rendered it almost impossible to ol)serve the surface characters at a final 
period of groAvtli. On one coral from Singleton, hoAvever, the mouths of tlie 
corallites are either round or polygonal, and the cell Avails rather more 
thickened than Avhen seen in transAmrse sections of the 2>eripheral region. 
Neither monticules, nor clusters of smaller cells, have been noticed. The 
interstitial, or inter-calicular surface, is always large in this species. 
