OCR Text |
Show 1873.] MR. G. KREFFT ON AUSTRALIAN CROCODILES. 335 The 5th tooth, counting from this notch backwards, is the largest of the upper series ; below, the 4th tooth is the largest. The genus Tomistoma is described as:-"Teeth jjpyg, the mandibular symphysis extending to the 15th tooth, and the intermaxillary bone reaching to the 2nd canine." M y specimen does not agree with this, and therefore it cannot belong to the genus Tomistoma. Of course, Dr. Gray could not know these facts, as he only had a photograph to go by ; and I remarked the difference only since the skin had been removed from the skull. A few days ago I received a fine and perfect skin of another Crocodile from Cardwell, through the kindness of Mr. C. Bloxland, jun., of Ryde, on the Paramatta river; and of this Crocodile, which I think is new to science, I shall give a short description. CROCODILUS JOHNSONI, sp. nov. Total length 7 feet, the head being 1 foot 4 inches. There are two groups of nuchal plates upon the neck, the first consisting of four disks of unequal size, divided by an interspace of about half an inch, the whole resembling in shape the figure oo. The second group, divided from the first by about 2 inches, may be compared to a distorted rhombic figure. It consists of two large disks, rather square in shape above, of a smaller pair below (all touching each other), and of an outer pair, one on the right, the other on the left side. All the disks are strongly keeled. A single disk forms the first dorsal row of plates, two disks the next, the third and fourth having four disks each ; after which follow two rows of six plates, and seven of eight, the outer ones being rather feebly keeled. The number of plates then diminishes again, there being two of six and four of four plates each, to the root of the tail. The total number of plate-rows from the posterior nuchal group to the base of the tail amounts to 19 in all. The tail is encircled by 29 bands up to the tip. The teeth number 16 * 16, the 10th above and the 12th below being the strongest. The hindermost teeth are short and conical, the rest being more elongate; and all are flattened on the inner side. The first pair of lower front teeth fit into perforations in the upper jaw. The narrowest part of the snout is contained nine times in its length from the nostrils to the eyes. Colour dark greenish, with some broad spots on the side of the tail. Discovered by Mr. Johnson, of Cardwell, Rockingham Bay, Queensland, and supposed to be adult. Australian Museum, Sydney, December 31, 1872. |