63 
So far as our investigations enable us to form an opinion, H. plasmoporoides is 
b * allied to H. megastoma, McCoy; indeed, in tbe figure of this species given 
si^ Haime we notice the onc-celled disposition of coenenchyma in places 
that seen in the present species. The latter, however, is clearly distinguished 
S', mcgastoma. {Nicholson and Etheridge fil.) 
Loo. Broken River, a tributary of the Clarke Eivei’. {The late It. Baintree.') 
Helioiites N'icuolsoki, sp. nov., PI. 1, fig. 12. 
Ileliolites, sp. iml., Nicholson and Eth. fil., Ann. and Mag. Nat. Hist., 1874, iv., p. 225. 
dii Corallura in the form of rounded or sub-lobate masses of small 
y . Corallites circular, separated from one another by intervals of coenenchyma 
■'^ith^”^ ^ millimetres in diameter. Calices very small, about |-mm. across, 
do thread-like margins ; septa delicate and short ; tabula) moderately 
Coouenchymal tubuli exceedingly delicate and small, 
dos( 
e. 
Microscopic, hexagonal or polygonal ; tabula) quite horizontal and moderately 
Hestl ■ tliii’d and small species of Ileliolites is represented by several examples 
tub 1™^ middle of a large block of Favosites. The calices and cmnenchymal 
‘^^etect’^^'^ ^®i'y small, the latter so much so that the use of a lens is required for their 
'hter vertical section the structure is characteristically heliolitiform. In the 
are between the corallites, the small square colls making up the coenenchyma 
apparent, but rather unequal in size. The tabula) in the corallites are 
stately close and horizontal. 
obg '^M.ces of very small septa remaining in one or two of the corallites have been 
surr their structure is so delicate and minute that their preservation is 
tbe M very probable that this is an undescribed minute Ileliolites, for which 
of Nicholsoni is proposed. It appears to be smaller in general than any 
^iibes species of Ileliolites, especially as regards the size of the coenenchymal 
Loo. Broken River, a tributary of the Clarke River. {The late R. Baintree.') 
Family— AULOPORID^. 
Oenus — AULOPORA, Goldfuss,l'&2iQ. 
(Petrpfacta Gorm.aniffi, i., I Theil, p. 82.) 
Attlopoiia HEPETfs {Knorr and Walch.), Edteards and Haime. 
^ulopora serpens, Goldfuss, Pctrefacta Gonn.aniie, 1820, I Thcil, p. 82, t. 29, f. 1. 
!> repens, Edwards and Haime, Polyi). Eos.s. Terr. Pal., 1801, p. 312. 
■” Nicholson and Eth. fil., Ann. and Mag. Nat. Hist,, 1879, iv., p. 282. 
” „ Hinde, Geol. Mag., 1890, vii. (3), p. 199, t. 8, f. 5. 
a ^o,ve an example of this interesting coral creeping over the surface of 
^siUoved lA^ -^e7?o7«Ves porosa. The weathering of the surface of the coral has 
the ratn'f and exposed wall of the Aulopora, and laid bare the interiors of 
' y>Dg or stolon-like corallites. {Nicholson and Etheridge fill) 
Polygon 1*^ enclosed by the union of the corallites are irregular in shape, some 
*^^eepiecf ‘ elongated. The corallites either occur along the course of the 
Ho thrown off as a small projection at each bifurcation. There is 
^^°Hg their disposition ; at one 2 )oint they succeed one another very rapidly 
®cattered^ tubes, and are much croivded ; but on other portions they are 
“'Hd separated by much greater interspaces. On the edge of the corallum, 
