61 
corallum ; vestibules deep ; interstitial surfaces strongly angular. Acantbo- 
pores small, very numerous, forming a more or less complete ring round 
each calico, and placed on the angular interstitial surface, superticially 
appearing as oblique rows, or encircling rings of small tubercles, or minute 
apertures. Moniliform annulations, or periodical tliickenings of the walls 
confined to the peripheral region, wide, and generally confluent towards the 
final period of growth, and thus becoming comparatively individually indis- 
tinct when separate, presenting an obconate appearance in sections. Tabuhe 
very sparingly developed, complete, but the calices sometimes closed by 
perforated diaphragms. 
Ohs . — In the case of this species identification has chiefly depended 
on Lonsdale’s figure in Strzelecld’s work, but the characters are so well 
marked that little difficulty has arisen in referring specimens to it. The 
figured example could not be found in the Department of Geology, British 
Museum, by the "Writer. 
As in S. ovata, the corallum is dichotomously branched, but, on the 
whole, S. tasmaniemis must be regarded as a less robust species than the form 
just named. The Inunches are sometimes enlarged and constricted in their 
course, and it not infrequently happens that the apices are hollow, from the 
apparent decay or disintegration of the corallites in the axial region. 
Lonsdale noticed^ this peculiarity, and both he and Dana speak of specimens 
crushed completely flat, with the whole of the axial portion removed. The 
base of attachment has not been observed, at the same time the species 
attained some size, as Lonsdale mentions one four and a half inches in length. 
As distinguished from S. ovata and A. Leichhardti, the peripheral 
region in the species now under description is remarkably narrow, arising 
chiefly from the very gentle angle at which the tubes diverge from the 
imaginary axis, the strong angle of deflection visible in other species being 
quite absent. 
The corallites in the axial region are angular, but become cylindrical 
throughout their short peripheral course. The j)i’imordial wall is visible in 
the former, and throughout a considerable portion of the latter, as very little 
secondary organic thickening appears to have taken place until the peri- 
phery of the corallum is approached. It is rare to meet with moniliform 
* Darwin’s Geol. Obs. Vole. Islands, 1844, p. 161. 
