I have dedicated this species to Dr. Fitton, who, independently of the numerous contributions to the geology of England, has always taken an active interest in the geology of the Australian continent.

Pecten squamuliferus. (Pl. XIV. fig. 1.)

Orbicular, depressed; ribs numerous, nearly equal, close, imbricated with small scales; ears large, unequal, triangular, similarly marked to the rest of the shell.

Locality.-Mount Wellington (Van Diemen's Land.)

BRACHIOPODA.

Terebratula cymbaformis. (Pl. XVII. fig. 4, 5.)

Form oval, ventral valve very gibbose, the mesial portion slightly flattened, and nearly straight from the beak to the front, which is truncate; beak of the dorsal valve large and prominent: the whole of this valve is very much incurved : length 2 inches, breadth 14 inch.

Locality.-Raymond Terrace (New South Wales). This is rather a remarkable form of Terebratula: the dorsal valve is regularly curved, so that the front margin and the beaks are level with each other. The surface of the shell is marked with concentric acute ridges.

Terebratula hastata. (Sow. Min. Con. t. 446.)

Two specimens from Illawara exactly agree with some varieties of this species from Bolland, Yorkshire they are of an ovate pentagonal form, with a depressed and slightly rounded front; the sides of the beak angulated; length 1 inch. The whole surface

of this shell is marked with the characteristic punctations of the smooth Terebratula, and which may also be detected in the corresponding species from Bolland, when carefully observed.

Locality. -Illawara and Raymond Terrace (New South Wales).

Spirifer (Terebratula?) crebristria. (Pl. XV. fig. 2.)

Shell transversely elliptical, depressed; mesial fold rather large, rounded and undefined; surface marked with numerous, fine, radiating, closely approximated striæ, crossed by the faintly prominent lines of growth; width exceeding the length by one fourth.

This species belongs to the Terebratuliform division of Spirifer of Professor Phillips, and would be more properly arranged under Terebratula, if the subdivision (Athyris) proposed by M'Coy be not generally adopted, as it agrees with certain species having many essential characters in common, viz., the radiately and concentrically striated surface, the absence of the area, the perforation of the dorsal valve, without a deltidium, &c., as may be observed in T. concentrica, T. undata, T. pectinifera, T. Roysii, &c., to which latter form our species is very closely related. It appears to be the representative form of Sp. glabristria (Phillips). The shell is elliptical and depressed, the lines of growth forming slightly prominent ridges.

Locality. Booral (New South Wales).

Spirifer Darwinii.

Shell transversely oval, valves equally convex, with three broad rounded ribs on each side, mesial lobe divided; beaks small; hinge-line short. Casts of this species have only been observed. It is a very neat

shell, and presents some resemblance to the young state of one of the varieties of S. subradiatus (Pl. XV. fig. 5a); the ribs, however, are much more prominent, and I have not seen any of very large size, and which occur as casts only in a sandstone from Glendon. Locality. Glendon (New South Wales).

I have dedicated this species to Mr. C. Darwin, who has very largely contributed to the advancement of physical geology and natural history generally.

Spirifer Tasmaniensis. (Pl. XV. fig. 3, 4.) Syn. Sp. rotundata, G. Sow. in Darwin, l. c. p. 159.

Shell transversely oval, front depressed; dorsal valve with about ten rather angular (sometimes furcate) ribs on each of the mesial furrow, which is broad, extending to the beak, and contains three or four ribs similar to the lateral ones; cardinal area broad, hinge-line as wide as the shell.

This is the same species as that described by Mr. G. Sowerby under the name of Sp. rotundata, in Mr. Darwin's work, before alluded to; that gentleman having kindly allowed me to inspect the original specimen. It is very distinct from the Sp. rotundata, Sow. Min. Con. In that species the mesial ridge and furrow are very nearly smooth; the lateral ribs are broad, flattened, and oblique, and the cardinal area very narrow; in our species the mesial ridge and furrow are equally costated with the rest of the shell; the lateral ribs are angular, sometimes imbricated; the cardinal area broad, and as wide as the shell. As justly observed by Mr. Sowerby, this is rather a variable species, the lateral ribs being more numerous on one than on the other side of the same valve. am inclined to regard his Sp. trapezoidalis var. as provisionally belonging to this species, from a com

I

parison of the specimens, although the latter form is very closely related to S. Stokesii.

Locality.-Eastern Marshes (Van Diemen's Land).

S. subradiatus. - (Pl. XV. fig. 5, 5 a. Pl. XVI. fig. 1, 4.)

Syn. Spirifera subradiata, G. Sowerby, in Darwin, 1. c. p. 159.

Shell transversely elliptical, smooth, nearly as long as wide, lateral surfaces, with a few undefined ribs, and numerous faintly elevated ridges, more visible in the cast; mesial ridge broad, bilobate, defined by a furrow on each side; corresponding mesial sulcation very large and wide. Beak of the dorsal valve prominent, hinge-line about half the width of the shell.

I have referred the specimens figured Pl. XV. fig. 5, 5a. to this species, first described by Mr. G. Sowerby in Mr. Darwin's Geological Observations on the Volcanic Islands, p. 159., presuming them to be the same, not having been enabled to examine the original specimens. There are two varieties of this species, one, as above described, with very faint lateral costa and a divided medial lobe; the other, in which these ribs are more prominent, the medial lobe undivided, the beaks more close, and the surface of the shell marked by numerous, minute, elongated punctations, more or less regularly arranged in a quincuncial manner; on the internal casts of this species, numerous longitudinal furrows may be detected on the lateral surfaces. Casts of this species are abundant at Mount Wellington, sometimes measuring four inches in width, and exhibiting a cast of the deep large muscular impressions in the dorsal valve; in the ventral valve, the dental lamellæ are obliquely placed on each side of the mesial lobe, and slightly arched in a portion

of their length. In the specimen figured Pl. XVI. fig. 2. the spiral shelly supports are beautifully preserved; one of them is distorted from the original position. Locality.-Illawara, Glendon (New South Wales), Mount Dromedary and Mount Wellington (Van Diemen's Land).

Spirifer avicula. (Pl. XVII. fig. 6.)

Syn. S. avicula, G. Sow. in Darwin, l. c. p. 160.

Transversely fusiform, nearly three times as wide as long; lateral ribs large, oblique, six to nine on each side, each one composed of three or four smaller ribs (scarcely visible in the cast); mesial lobe prominent, ribbed; hinge-line straight, as wide as the shell, with pointed ends; width, 41⁄2 inches; length, 1 inches.

Three or four ribs in this species are grouped together, forming about six to nine prominent ones on the lateral surfaces: the dorsal muscular impression is tongue-shaped, with a divided furrow, and depressed. Mr. Sowerby mentions that the posterior inner surface of both valves of Sp. vespertilio is covered with distinct punctulations, but in this species it is the dorsal valve only that has been punctulated.

Locality.-Eagle Hawk Neck (Van Diemen's Land).

Spirifer vespertilio. (Pl. XVII. fig. 1, 2, 3.) Syn. Spirifer vespertilio, G. Sow. in Darwin, l. c. p. 160.

Transversely fusiform, with distinct, angular, imbricated ribs, 15 to 20 on each side; ventral valve with a prominent mesial ridge, extending to the beak, bearing 2 to 5 ribs similar to the lateral ones, and a corresponding deep, broad furrow on the dorsal