hab. Western Australia, near Swan River.

3. The Port Essington Cray-fish. 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 vis