13 
Serpula sup.tkachinus, ,s7>. nor. 
(PL YIL, Fig. 10.) 
Sp. Char . — TuLes solitary, tally attached hy one surface, tlexuous, 
or possessing some degree of curvature, -witliout coil or helix, attenuated 
posteriorly, carinate ; section triangular to obtusely triangular ; carina tine, 
median, anteriorly terminating in a groove ; aperture triangular, neither 
thickened, nor unduly enlarged. Surface transversely and delicately corrugate, 
liere and there one corrugation slightly more prominent, or coarser than the 
others, the corrugations inflected, or inhent towards the carina. 
Ohs. — It is difficult to assisrn a name to this rather common form of 
Serpula, hut with the exception of size, it is very close indeed to S. ( VermUia) 
trachinus, E^oemer [+*S'. [VermiUa) Jophioda, Ptoemer].^ In one instance two 
tubes are partially joined together laterally, all the others are solitary. As in 
many other Serpulce, the carina appears to end anteriorly in a line of least 
resistance forming a groove. 
Log. — Mount "VYilson Well, Dunlop Station, thirty miles west-north- 
west of Louth, Darling Piver, North-West N. S. Wales. 
Hor. — Lower Cretaceous. 
Colin. — Mining and Geological Museimi, Sydney. 
POLYZOA. 
Genus — MEMBRANIPOPA, De Blainville, 1830. 
(Diet. Sci. Nat., 1880, LX, p. 411.) 
MeMBRANIPORA ? WILSONEXSIS,^ Sp. IIOV. 
(PI. VIII, Figs. 11 and 12.) 
Sp. Char. — Polyzoarium apparently circular when mature, and 
incrusting, covering a surface of two and a half inches hy one and a half 
inches. Zocecia radiating from a common centre, and very regular in their 
habit of growth, uniform in size and appearance, elongately hexagonal in 
outline, one millimetre in length hy half a millimetre in breadth, the 
proximal half of the hexagon generally narrower than the distal ; boundary 
Avails between the lines of zocecia very distinct, and slightly zig-zag aiising 
^ Goldfuss, Petrefacta Germania?, 2il Edit., 1802, pp. 210-220, t. 70, f. 1 and 2. 
^ So named from tlie locality yielding it, Mt. Wilson NV'ell. 
