Furthe({ Permian Corals from Western Australia. 
()7 
Thamnopora insculpta sp. uov. {Plate I., figs 9 a-d ; 
Plate II., figs. 8 and 9). 
Type material : Eleven fragments, possibly from one specimen, from 
the Callytharra beds near Callytharra Springs, W.A., collected by C. Toichert. 
Diagnosis : Slender l>ranching Thamnopora with the corallitos opening 
a little obliquely to the surface, dilatation of the walls increasing greatly 
towards the surface, so that the openings are distant, and sunken into the 
unridgod, faintly tuberculated wall tissue. 
Description : The diam(?t(‘r of the cylindrical branching fragments varies 
between 3 mm. and 10 mm. The calical oponings are unequal, the largest 
being P5 mm,, some being 1 rnm., and a few 0*5 mrn. in diameter. They 
are unetiually spaced, the smaller being in the angles b(‘tweon the larger, 
which tend to be arranged in voi’tical rows. The ojienings are occasionally 
surrounded by a raised rirn, especially n(!ar the growing tips of the branches, 
its height being gn^atest on the under side of the opening, but in the older 
branches there is usually only a very faint trace of this rim, and that on the 
xmder side of the opening. Potwixm tlui openings there is instead from (0 5 
to 3 mm. of dense sclonaichymo, which is lightly tuborculate, and no trace 
■of the junction between the walls of lu'ighbouring corallitos can be seen. 
Faint septal ridges are obse vahle in one or two calicos, twelve being counte<l. 
The corallit{>s are almost vertical in the axial parts of the brancJi, and very 
small, being from 0*1 to 0-5 ixim. in diameter, with but slightly thickened 
walls. Outside this axial part of diameter about 2 mrn., tlie corallib^s bend 
rather rapidly outwards, opening to the surface at k^ss than 30^ to the hori- 
zontal. As they proceed to the surfaeo they increase in diameter, l>ut the 
greatest j>art of this incn'ase is duo to an increase in the thickness of the 
walls, the lumen never becoming wider than 1*5 mm. The walls may bo 
very thick, from the <Iark line ropresonting the junction of two corallitos 
to tlie inner friges of the septa may bo as much as 1*5 mm. The fibrous 
structure of this thickened tissue shows that it consists of twelve equal septa 
so dilated as to be in contact laterally. The vertical sections suggest that 
they have denticulate imior edges ; but individual tralx'culae are not 
distinguishable in the fibrous tissue, as septal spines. Mural p(jn*s are fairly 
frequent, small and regiilai'. Tabulae aro thin and distant. 
Remark's: The generic ]KJsition of this species is iloubtful. The occurr- 
ence of tweh e ecjual se])ta is a character suggestive of generic (.lifference from 
Thamnopoi'a cervicornis, since neitlier sojda nor septal spines aro knovai in 
the types of T. cervicornis. Spficies with septal sj^ines have been included 
in Thamyiopora, but j^ossibly this Western Austi*alian .sx>ecies with lamellar 
septa should be placed in a separate genus with the eastern Australian 
Trackypora wilkinsoni Etheridge, to wliicli it is very close. T. wilkinsoni 
has the twelve lamellar septa much more clearly developed, and in it the 
■outer boundaries of the individual corallites are distinguishable by ridges 
on the surface. T. xvilkUisoni occurs in the Upper Marine of Mulbring, and 
of Ellalong, N.S.W., in the Coral Stage of the Bow'on Marino of the Spring- 
sure Basin, Queensland, and in the Condamiiio Fault block, near Silvorwood, 
Queensland. I have not .seen it from Western Australia, hut T, insculpta 
appears to mo to bo a related form. Favosites permica Gerth (1921, p. 101, 
pi. cxlix., figs. 1, 2, 3, pi. cl., fig. 1) from the Basloo Beds, also has twelve 
septa, lamellar in the upper part of the calico, but this form is encrusting. 
Its septa consists of spines fused together at their bases, forming a series of 
stripes on tho calical floor, but with separate spine ends in the lumen. Twelve 
septa, sometimes acanthine, but frequently with the spines fused at their 
