334 MR. G. KREFFT ON AUSTRALIAN CROCODILES. [Mar. 18, 
3. Remarks on Australian Crocodiles, and Description of a 
Ne\r Species. By Gerard Krefft, F.L.S., C.M.Z.S.* 
[Received February 17, 1873.] 
About a year or two ago I sent to Dr. Gray the photograph of a 
Crocodile's skull, which he examined and considered tobeundescribed. 
Tbe name of Tomistoma krefftii was proposed for it ; but I cannot 
find the description in any of the works at my disposal. 
During the process of cleaning and bleaching the skull, it was in- 
jured by rats, and the end of the snout is now broken and some teeth 
lost ; otherwise it is in tolerable condition, and appears to agree with 
Croeodilus schlegelii, as figured by De Blainvdle (Osteographie, 
Atlas, vol. ii. pi. 5), with this difference, that the mandibular sym- 
physis extends to the 1 5th tooth in C. schlegelii, and to the 6th 
tooth only in T. krefftii (Gray). There are 18, or perhaps 19, teeth 
above, and 1 5 teeth below, on each side, a notch being observed be- 
hind the 4th (or 5th) tooth, with a small pit for the lower canines. 
* Tbe following letter, referring to tbis paper, has been addressed to tbe Se- 
cretary by Dr. J. E. Gray, F.E.S. :— 
Sir, — Mr. Erefft has just sent to me the photograph of a Crocodile from Aus- 
tralia, which he has named Croeodilus johnsonii, with the request that I would 
communicate to the Society some observations upon it. 
Tbe photograph is about 22 inches long, and represents the dorsal view of the 
animal. 
There is no doubt that it represents a species of Crocodilida, from the form of 
the cervical and nuchal shields ; but in many respects the beak is similar to that 
of Tomistoma, the Bornean Gavial. The beak is more slender than in any 
tvpieal Crocodile of tbe Old World that has occurred to me. It is somewhat like 
that of Molinia intermedia, from tbe Orinoco, figured in the Trans. Zool. Soc. 
1869, vi. p. 151. f. 4, 5, and pi. 32. f. 4^6 ; but it differs from that species in the 
beak being more slender, not being swollen on the sides, or so broad and circular 
at tbe end, and also in the shields of the neck and back, which are very 
different. 
In many respects the appearance of the animal, and the form of the beak, are 
much like (especially in the want of dilatation at tbe sides, and in the moderate 
breadth of the end) those of the African false Gavial, Mecistops cataphractus; but 
it has well-developed lateral cervical shields, which are wanting in all tbe African 
specimens I have hitherto observed ; and one cannot understand how a West- 
African Crocodile can have been taken to or found in Australia. 
Judging from the photograph, I believe it to be a new species of Crocodile ; 
and the form, as far as I know, is peculiar to Australia. 
I am, Sir, 
Tours truly, 
Joh>" Edw. Grat. 
P.S. — I strongly suspect that tbe photograph of the head for which Mr. Krefft 
says I had proposed the name of Tomistoma krefftii belongs to Croeodilus john- 
sonii. 
The examination of a photograph of the upper part of the head would induce 
one, on account of the slender conical form of the beak and tbe absence of large 
canine teeth, to consider it a species of Tomistoma ; but the examination of the 
photographs of the skin, showing the eight cervical plates separated from the 
dorsal shield, and the short symphysis of the lower jaw, mentioned by Mr. Krefft, 
show that it is a Crocodile, and not a Gavial. 
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 fg— fjj, the mandibular 
symphysis extending to the 15th tooth, and the intermaxillary bone 
reaching to the 2nd canine." My 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 ; aud 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 Cro- 
codile 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. 
Crocodiltjs 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 fol- 
low 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 en- 
circled by 29 bands up to the tip. The teeth number jfjp-jf, fc ^ e ^ tn 
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.