of the back.  It terminates beneath the sixth ray from the end of the fin, but recommences on the fourth scale beneath, and runs in the middle height of the tail to the base of the caudal.  Two or three of the scales before its recommencement, have a minute pit in the middle of their disks, as is not unusual with the Glyphisodons.  The first part of the lateral line forms an almost continuous tubular ridge traced on thirty-eight scales of the second row from the summit of the back; the posterior part traverses six or seven scales.  There are twelve or thirteen scales in a vertical row on the side of the body.

The anus, situated a short way before the anal fin, has a very small aperture.

There are no scales on the fin membranes.  The three dorsal spines are short, graduated, moderately stout, and pungent.  The twenty-three soft rays are all distinctly articulated, and more or less branched.  The last ray is divided to the base, and is graduated with the two preceding ones, giving a rounded form to the posterior tip of the fin.  The specimen had the anterior part of the fin frayed a little, so that it is probable that the soft rays are higher and less distinctly branched than the artist has represented them to be in copying the example placed before him.  The ventrals are in a line with the tip of the gill cover and first soft dorsal ray, and from the extreme narrowness of the pelvis are close to each other.  They are tapering, pointed, and overlap the beginning of the anal, which, though it have fewer rays than the dorsal, is similar in structure.  The pectoral and caudal are much rounded, especially the latter.  There is a greater space between the anal and caudal than between the dorsal and the same fin.  In the caudal there are twenty rays, including two very short ones above, and the same number below.

The general colour of the specimen, which has been long in spirits, is shining yellowish-brown with several round dots of azure-blue scattered over the body.  The cheek is crossed obliquely by a row of three spots.  The figure errs in representing the spots as dispersed over the cheek; they are in fact ranged in a row.  Length, 2 1/2 inches.

HABITAT.  Coast of Australia.

Haslar Hospital, 28th October, 1845.

...

APPENDIX.

DESCRIPTIONS OF SOME NEW AUSTRALIAN REPTILES.

BY JOHN EDWARD GRAY, ESQUIRE, F.R.S., ETC.

...

Fam.  SAURIDAE.

SILUBOSAURUS, Gray.

Head subquadrangular, raised in front, head-shields flat, thin, rather rugose.  Nasal shields ovate, triangular, rather anterior, with a groove behind the nostril.  Rostral shields triangular, erect.  Supranasal none; internasal broad; frontonasal large, contiguous; frontal and interparietal small, frontoparietal and parietal moderate; eyebrow shields, 4-4.  Temples scaly, no shields between the orbit and labial