ASTACUS BICARINATUS, t.

3.f.
2 .-- Carapace smooth, rather flattened, with a keel on each side above in front; the beak longly produced, flattened, three toothed at the top; hands rather compressed, smooth, thinner and slightly toothed on the inner edge; the wrist triangular, angularly produced in front; the central caudal lobes with two slightly diverging keels continued, and like the others thin and flexible at the end, the inner lateral lobes with two keels, each ending with a spine.
Inhab.

Port Essington, Mr.Gilbert.
The A.AUSTRALASIENSIS, Milne Edwards, Crust ii.332.t.24.f.

1--5.
agrees with this species in the form of the beak, but the keels on the thorax are not noticed either in the description or in the figure; and the caudal lobes in the figure appear most to resemble A.FRANKLINII.
As the genus ASTACUS is now becoming more numerous in species, it may be divided, with advantage, into three sections, according to the form of the caudal lobes; thus:-- A.The central caudal lobes divided by a transverse suture into two parts, both being hard and calcareous, and with a small spine at the outer angle of the suture (PATAMOBIUS, LEACH) as A.FLUVIATILIS of Europe, and A.AFFINIS of North America, with an elongated rostrum, and A.BARTONII of North America, with a short rostrum.
B.The central caudal lobe continued hard and calcareous to the end, as ASTACUS FRANKLINII of Van Diemen's Land, and A.MADAGASCARIENSIS of Madagascar; both have a very short beak, and the second abdominal ring spinose.
C.The central caudal lobe continued or only slightly divided on the middle of each side; but it and all the lateral lobes are thin and flexible at the hinder parts, as ASTACUS QUINQUE-CARINATUS, and A.
BICARINATUS of Australia, and A.CHILIENSIS of Chili.
CATALOGUE OF REPTILES AND FISH, FOUND AT KING GEORGE'S SOUND, BY DEPUTY ASSISTANT COMMISSARY-GENERAL NEILL, IN A LETTER TO J.E.GRAY, ESQ.

BRITISH MUSEUM, LONDON.
* * * * * "Sir,--Although in the course of my life, I have had little opportunity to pay attention to the study of Ichthyology, it occurred to me, as now and then a leisure moment was afforded from official duties, that it would perhaps be useful, as well as amusing, to collect and make drawings of the fish about King George's Sound; and I have been in a great degree stimulated to do so, from an accidental visit of my friend, His Excellency Captain Grey, Governor of South Australia, who advised me to forward the drawings to you for the purpose of being placed with others of a similar kind in the British Museum, where ultimately sufficient material may be collected to give some account of the New Holland fish.
"Nothing is assumed as to the execution of the drawings; in fact it often occurred when I set off in my little skiff, (especially in the outset) that seven or eight species were procured in the course of the excursion, which compelled me to make drawings of all when I came home tired in the evening; forwarding them to ensure, as far as possible, their colours before they became extinct--a sort of forced effort in respect to the execution has, therefore, only been effected.