28 
A peculiar instance of contrariety of growth is sliown in PL I, Pig. 3, 
where the calicos at either end of the specimen have grown in opposite 
directions opening towards one another. 
Trachyioora Wilkinsoni is, with Stenopora crinita^ one of our most 
characteristic^ corals of the Upper Marine Group. 
Locality and Horizon. — Mulbring (Mount Vincent), near West 
INfaitland, Co. Northumherland (Jflessrs. T. TU. E. Eavid, E.A., C. Cullen, 
— Twine, and S. Eodds) ; Earren Plat, Shoalhaven District, Co. St. Vincent 
{II. Moss); Shoalhaven, Co. St. Vincent (C. Cullen)-. — Upper Marine Series. 
Eooroolv,“ Co. Buller (_D. jI. Eorter) : — ? Upper Marine Series. 
Genus — MICHELINIA, De Koninck, 1842. 
(Descriji. Anim. Foss. Terr. Carb. Belgique, Fas. 1, p. 29.) 
Micuelinia, sp. 
Plate IV, Fig. 1. 
(Comp. MicheUnia tenuisepta (Pliill.), Edwards and Ilaimc, Mon. Brit. Foss. Corals, 1852, Pt. 3, 
p. 155, t. 41, f. 1, 1 a-h. 
Ohs. — A portion of a small specimen represents the only example of 
this genus wdiich has come under my notice from Australian Permo-Carhon- 
iferoiis rocks. The specimen has been broken across, and, although somewhat 
obliquely, the character of the corallites is well displayed. The epitheca is 
not well preserved, nor are there remaining any radiciform processes, even 
if the species possessed them, which I think doubtful. The calicos are from 
seven to nine millimetres wide, but as the surface has been fractured obliquely, 
the actual diameter would be less. The tabulce, from their peculiar arrange- 
ment, give rise to the characteristic vesicular tissue, the vesicles being small 
and very numerous, but there are no septa visible. The walls of the corallites 
are moderately thick, and freely pierced by numerous irregularly-placed pores, 
giving to them under the hand-lens a slightly cribriform appearance. Vertical 
s 2 )inuies on the tabulre are not visible. 
* The original specimens used by me were limited in number, and poor in outward preservation, compared 
with a very fine and large collection since made at Mulbring by Mr. Cullen. Many of these exceed the 
measurements given above, but tlie largest fragment which has come under notice is a specimen three inches 
long, witli a diameter of one and a quarter inches, presented by Mr. Twine. 
^ The ultimate geology of this district appears to be but little known. In the late Mr. Lament Young’s 
“Report on the Boorook Silver Mines” (Ann. Report Dept. Mines N. S. Wales for 1878 [1879], p. 85) the 
silver lodes are said to be associated with shales of Upper Devonian age. The fossils, however, wliich have 
come under my notice so far from this locality do not differ from those of the Permo-Carboniferous areas. 
