examined, but they did not admit of a complete identification.

Locality.-Mount Wellington, Mount Dromedary, Norfolk Plains, Van Diemen's Land.

Stenopora ovata. (Pl. VIII. fig. 3—3b.)

"Branched, branches oval; tubes relatively short, divergence great; mouths round; mouths round; contractions or irregularities of growth numerous." (Op. cit. p. 163.)

The structure of this species was not fully exhibited in the specimens originally examined; but in Strzelecki's series was a fine ramose coral, believed to be identifiable with Sten. ovata, as it possessed characters in accordance with those previously noticed: it supplied also others, which confirmed the inference, that this fossil is specifically distinct from Sten. Tasmaniensis.

The beautiful specimen alluded to, consisted of a main cylindrical branch, 3 inches in height, 7 lines in diameter at the lower extremity, and 4 near the upper, where the curvature of the termination commenced. From this branch several others, varying in width from 2 to 7 lines, diverged either obliquely or at right angles: the tubes sprung successively from an imaginary axis, but with numerous interpolated additions, and radiated more or less rapidly, sometimes at very obtuse angles. In the centre of the branches, and before the deflection became marked, they were in contact and polygonal; and the contractions, though relatively distant, were very decided, giving that portion of the coral a pecuculiar aspect, and indicating apparently periodical renewals of growth. In no case, however, was there a satisfactory proof of the mouth of the tubes having been perfectly closed, as noticed on the exterior of a branch of Sten. Tasmaniensis, believed to mark a condition of the ultimate stage of developement. From

the points where the rapid divergence commenced, the tubes were more or less separated and cylindrical; and the contractions became very numerous, though each series was singly not so conspicuous as in the centre of the branches. The casts of the mouths, so far as they could be ascertained, were round, and instead of being encircled, as in the preceding species, with a row of granules or indentations, there was only a single impression of a relatively large tubercle at the cast of the interspace between four mouths, where the rows occurred regularly or between a less number where such was not the case.

Locality.-Mount Wellington, Mount Dromedary, Norfolk Plains, Van Diemen's Land.

Stenopora informis. (Sp. nov. Pl. VIII. fig. 4, 4a.) Amorphous; tubes cylindrical, slender, unequally divergent; contractions variable.

This coral was considered to be distinct from the two preceding species on account of its mode of growth, and its affording no grounds for inferring that the specimens had formed the base of a ramose polypidom.

The section of this Stenopora which was examined was imbedded in a fragmentary rock cemented by a felspathic paste, and the whole of the calcareous or original substance of the coral had been removed. The exposed surface was irregular in outline, but the greatest width was two inches, and the greatest height one and a quarter. The diameter of the internal casts of the tubes was about a quarter of a line. Near the base of the specimen the tubes were vertical for a limited portion of the upward range; but even there, they exhibited no signs of lateral compression. The degree of divergence was very unequal, amounting in some places almost to the curvature of a quadrant, and gave the section the appearance of being composed

in part of dislocated fragments. The distance between the contractions also varied considerably, being often very small, but the lines of indentations had a great persistence their parallelism, however, was limited on account of the irregularities in the mode of growth. The imbedded position of the coral completely prevented the characters of the tubular mouths and of the interstices from being ascertained. The original walls of the tubes were, as in the other species, apparently very thin, except at the points of contraction. Numerous examples of interpolated tubes were noticed.

Locality.-Spring Hill, Van Diemen's Land.

Stenopora crinita. (Sp. nov. Pl. VIII. fig. 5, 5a) Hemispherical or globular; tubes polygonal, slender; contractions distant.

This fossil has a great general resemblance to the Chatetes of M. Fischer de Waldheim, particularly to Chat. radians, (Oryct. Gouvern. de Moscou); but it is distinguished by the contractions characteristic of Stenopora, and by the additional tubes having been essentially produced by interpolations.

The specimen examined consisted wholly of calcareous spar, and formed part apparently of a globular or hemispherical mass, which must have possessed considerable dimensions, the radius of the fragment being 4 inches. The tubes were about one-third of a line in diameter, and radiated in general very slightly; but they were irregularly bent in some portions of their range. They were polygonal throughout, both externally and internally, except at the contractions; and the infiltered calcareous matter had not only filled the interior of the tube, but had also replaced for the greater part the substance of the original walls. The contractions, as exposed in

a vertical section, presented series of parallel, transverse, slight indentations, from one to two lines. apart, indicating a perfectly simultaneous process in the polypes; and even young or interpolated tubes, which commenced almost immediately below a row of indentations, exhibited as marked a contraction as the adjacent fully developed columns. In the superior terminal surface, as well as in transverse fractures in the plane of the contractions, the tubes were lined by a narrow band, slightly varying in breadth, but never approaching to the nature of a diaphragm.

Perfect terminal mouths were not observed: and in the instances on the upper surface of the specimen, which exhibited the most advanced state, the mouths were defined by white lines more or less circular, and separated by small intervals of a darker colour. The additional tubes were irregularly interpolated, and sometimes sprung from the lines of contraction, but sometimes commenced in the spaces between them. In the former cases the inferior terminations were generally more or less obtuse, while in the latter they were usually very sharp. The form of the adjacent mature tubes was more or less influenced by the interpolations, owing apparently to the expanding pressure of the growing young polype.

Locality.-Illawara, New South Wales.

Favosites Gothlandica? (Lamarck.)

Of the fossil assigned with a doubt to this species of Favosites, several specimens were included in Strzelecki's collection, but the mode of preservation did not permit their characters to be fully ascertained. In one instance only was a succession of connecting foramina detected. It constituted a single row of round or oval openings, much larger than in the ordinary Favosites Gothlandica of Europe, but very similar to the foramina of an American coral in Mr.

Lyell's cabinet, and believed to be only a trans-Atlantic form of Lamarck's species. Whether the Australian fossil varied in the arrangement of these connecting openings, and agreed with the American and European in having sometimes one, sometimes two, rows of foramina on the same facet of a column, or whether it possessed uniformly a single row, and consequently a specific difference, could not be determined. It was, therefore, deemed advisable to assign the specimens provisionally to the nearest known species. Locality. -Yass Plains, New South Wales.

Amplexus arundinaceus. (Sp. nov. Pl. VIII. fig. 1.) Oval; exterior longitudinally ribbed, transversely annulated; septa slightly convex or flat, margins faintly crenulated.

This Amplexus differed from the published species known to the describer, by the rounded longitudinal ribs and transverse annular irregularities. In external aspect it resembled some coal-measure calamites.

The length of the finest fragment examined was about two inches, and the major and minor axes were respectively 7 and 6 lines; but in the same mass of black limestone were other portions, of slightly smaller dimensions. The crenulations near the margins of the septa or diaphragms were unequal in range as well as strength, and in some cases they were scarcely detectable. In one instance, under a favourable oblique light, converging radii were traced from nearly half the periphery of the oval, across more than twothirds of the area; but the opposite extremity of the diaphragm was uneven, and not traversed by radii or crenulated. The most marked convex irregularity was exhibited in the superior septum, and resembled that delineated by M. de Koninck in one of his figures of Amp. coralloides (Amp. Sowerbi, Phillips), and there was a further agreement in the Australian fossil