41 
Prof. NicliolsoiP “ spiiiiform corallites,” aucl by Messrs. Nicliolsoii and 
Poord^ “ acantliopores. They are, apparently, the “ wandrolirchen ” of 
DyhowskP, and the “ nendy-developed gems” of Messrs. TV^aagen and 
WentzeP. I liave only had an opportunity of macroscopically examining two 
Australian species, S. tasmanieiisis and S. ovafa. The characters of the 
surface in the first will he found under its specific description, hut in S. 
ovata the acanttiopores do not apjiear to have that marked spiniform appear- 
ance so noticeable in the former species. This, however, may perhaps ho 
due to imperfect preservation. 
In sections of the characteristic Kew South Wales species, S. crlnila, 
acanthopores are of variable occurrence. They appear in some specimens at 
all the angles between the corallites, hut in other cases whole sections may he 
examined without a single acanthopore being present, notwithstanding that 
the walls of the corallites are thickened. In S. ovata the acanthopores arc 
of large size, almost always at the angles, and very frequently on the inter- 
stitial surface. In S. australis, acanthopores have not, so far, been observed ; 
hut in S. Leichhardti they are irregularly scattered, as in S. ovata. On the 
other hand, in S. tasmaniensis these bodies form one of the most characteristic 
surface features of the species. 
In a longitudinal section, say of S. ovata, the acanthopores appear as 
fibrous strings in the walls of the corallites, and usually possess a similar 
fibrous structure when thickening has taken place. In some cases, althougli 
not often, the acanthopore tubes appear hollow, filled with clear calcite, and 
the walls strong and determinate, but these need not in any way be con- 
founded with young corallites. It is, however, in horizontal sections, 
whether tangential or axial, that the structure of these bodies can be best 
interpreted. In sections of an entire braneh, wherein both the vertical, 
peripheral, and axial horizontal can be studied, the acanthopores are usually 
visible in the latter, at the angles of the corallites, as dark bead-lilce spots, 
probably representing, as suggested by Messrs. Waagen and Wentzel, their 
initial stage. It is then easy to trace the relation of these bodies to the 
fibrous strings, or hollow tubes, as the case may be, visible in the former 
portion of the sections. 
’ Genus Monticulipora, &c., 1881, p. 45. 
* Ann. Mag. Nat. Hist., 1885, XVI, p. 497 [note). 
^ Die Chaetetiden der Ostbaltisclien Silur-Formation, 1878, p. 9. 
^ Pal. Indica, Salt Range Fossils, 1886, Vol. I, Part 6, p. 871. 
