32 
CHETACEOUS CORALS OR zVXTHOZOA 
granidatis inter calyces distinctis; sejrtis in trihiis cyclis rcg ularihus disjjositis; 
exotheca late celliilosa. 
Judging from a fragmentary specimen, the corallum appears to be largely 
expanded, with a rather flattened upper surface, and from 30 to 10 mm. thick. The 
calyces arc rounded or roundly ovate, moderately distant and irregularly distributed, 
with raised margins and granular well marked costae, which, however, very easily 
Avear otr, and then the interspaces between the calyces remain irregularly granular 
or even smooth. There are three complete cycles of septa, those of the first order 
conspicuously thickened and not distinctly separable from the large spongiose colu- 
mella. All the septa arc above granular and laterally densely and finely denticulate. 
The exothcca is formed in almost parallel horizontal layers, and is largely cellular. 
Locality . — Xorth of Odium, in a coarse calcareous sandstone; apparently rare. 
Formation . — Ootatoor group. 
2. ? IIeliastrba, sp. indet. PI. Ill, Fig. 5. 
A fragment of a Ueliastrea^ differing from the previous species by a greater 
distance of the calyces from each other, has the whole surface so much worn off 
that no definite characteristic can he given of the species. There are three cycles 
of septa, but those of the third cycle arc very small and sometimes obsolete. The 
primary septa are attenuated towards the centre. The cxotheca is very largely 
cellular, and in horizontal, parallel layers. 
iocad/Vy.— South-west of Penangoor; the single specimen is partly silicified. 
Formation . — Ootatoor group. 
3. IIeliasthea eotexda, Stolicska. PI. VI, Fig. 3. 
Heliast. corallum crassim, orhiculare, supra et infra lente coneexum; calycihus 
3 4 mill, latis, suh-rotundatis, vel rotundate polyyonis, margine paulo elevatis, 
interspatiis angustis paulisper ptrofundis separatis, septis in tribus aut quatuor cyclis 
dispositis, cyclo quarto imyerfecto, tenuibus, dense atque minute gramilatis, later- 
aliterqne minulissime spinulatis ; columella lata, spongiosa. 
An orbicular corallum, almost equally convex above and below, the upper sur- 
face of which is partially caA'crnose, the cause of which, howevei’, appears to be 
merely accidental. The calyces are irregularly and rather densely distributed o\er 
the entire upper side ; they have slightly elevated margins, and arc separated by 
rather shallow and narrow depressions ; the diameter of each calyx A'aries from 3 to 
4 mm., and the shape in younger specimens is generally quite circular, approach- 
ing to roundly polygonal in the more adult. The septa are thiu, granular ahoAC, 
finely denticulate at the sides ; there are three complete cycles of them, and the 
larger calyces have besides a fourth incomplete cycle, the total number of septa 
thus varying from 24 to 40. 
( 'l64 ) 
