31

March Abrolhos Shoals

1832

Oily matter on sea displayed iridescent colours & were often time two inches in diameter.— (d) A drop of water under a microscope showed on its surface minute globules of a transparent floating liquid, & which from its feel was of an oily nature.— it contained likewise irregularly shaped transparent minute fragments of matter: Three quarters of an hour after I first observed this appearance it was no longer visible. the ship in that having sailed 2 & 1/2 knots.— I am at a loss to conjecture what could have been the origin of such a quantity of oily matter; it is stated that whales often produce this effect.— At night this water showed luminous particles.—

Oily matter (c) 27th at 10 AM the sea for yards was coated with the oil, having an iridescent appearance: It was in patches or streams & extended for a considerable distance.—

Oscillaria (a) (390:391 not spirits) (e)

At noon Lat 17°43′ S & Long 37°23′ W my attention was called by Mr Chaffers observing that the sea was in places discoloured.— Even from the Poop the cause was visible. it was owing to the presence of numberless minute whitish particles: These when examined under a lens whose focal distance was under above 1/10 of inch appeared like bits of chopped rag, the ligneous fibres of which projected beyond the end.—

[31v]

(a) It required a 1/30" focal lens in order to see the internal tube.

[in margin:] No soundings at this spot.— But 6 knots before 36 h.

x At noon on 31st of March, Lat 19°52′ S, Long 38°7′ W, the ship passed through a band of these Oscillariæ a mile in width. I reexamined them.— The bundles were often cylindrical, containing from 20...to 60 fibrils.— a large one taking the extreme points was in length was .03 & in breadth .009.— Fibrils were perfectly straight: varied much in length; were I presume enveloped in a fluid.— as in many of the bundles the fibrils did not touch each other.— Being kept till the following morning the particles became of a much brighter green & were partially decomposed: a considerable quantity of brownish flocculent matter lying at the bottom of the cup.— The fresh Oscillaria placed in Alcohol uncoiled, moved these & finally burst.— These appearances are called by the Sailors Spawn.— At 4 PM we passed through another irregular band running E & W.— about 10 yards wide & about 2 & 1/2 miles long.— The sea was the colour of thick reddish mud.— I believe each bundle of Oscillaria touched another.— I judge of this likewise by the thickness of the covering on some water brought up in a bucket.— (At this rate in this narrow band & at a [tide] moderate computation, in each square inch of surface there must have been 499950 fibrils or separate Oscillaria.— In the whole band: 323 967 600 00[0] 000: or 323 millions of millions &c.—?) Perhaps in square inch about 100 000.

32

March Abrolhos Shoals

1832

Oscillaria x These particles seen under a higher power consisted of about 20 fibrils adhering side by side & forming either a flat or a nearly cylindrical bit of mat.— These cylin fibrils or stalks were in length from .02 to .03 of inch; in diameter 1/2000: extremities round, rather broarder, transparent; internally a tube (a) containing concentric layer of greenish brown granules. Hence appearing jointed: these layers are close to numerous. The external tube was marked by fine circular rings. (??)

I once thought that I perceived a motion in these fibrils: from the description in & 31 (b) Dic. Class.7 I suppose it is an Oscillaria.— After being kept for an hour in water, most of them fell to the bottom of the Basin, & it appeared to me that in this state all the granules had been expelled: Figures are quite inadequate to give any idea of the numbers of these groups of Oscillaria which the sea contained.— A bucket which had been lowered for some water, had its interior sides (being left for short time at rest) literally coated with these minute particles.— I should think they extended for some distance; The sea 3 hours afterwards contained a few.—

Conferva (b) 392 not spirits On 28th; 10 miles West of Abrolhos; there came up with the lead (17 fathoms) a piece of Fucus.— on which were growing numerous minute tufts of a Conferva8.— Stems simple cylindrical white transparent jointed; end truncate; length 1/10 of inch, diameter 2/3000.— On this minute

[32v]

(a) 169 Spirits

(b) 393 not spirits

(c) 175 Spirits

33

March Abrolhos Shoals

1832

Conferva (b) plant & on a small coralline were crowded together a forest of numerous species of Bacillareès & Anthrodieès.

Phasianella (a) Animal with foot marked with black.— body blueish-lead colour; between feelers claret coloured.— feelers ringed with black.— these were nearly the only shell on coast of the Abrolhos.— they were however in the greatest profusion covering the rocks, & what appeared to me very singular, crawling up a bush which grew within high water mark.— The shells adhered to their leaves & bark far above the reach of the waves: From the habits when kept it is evidently an animal which passes much of its time out of the water.— Abrolhos.— March 29th.—

Tubiporèes (c) (Gorgonia?) (Lamouroux ??) Abrolhos. 20 fathoms. March 30th.— Corallina, branched, stem rather flattened, horns, hollow.— Polypi when not expanded like buds scattered irregularly on sides & extremities of branches.— Stem slightly encrusted with red stony covering.— Polypi white, length .15, tentacula 8 in number, fimbriated. when partly collapsed having a leaf like appearance.— Tentacula situated on a fleshy tube proceeding from a slightly coriaceous one or cell.— Polypi highly irritable: but when fully expanded the Corallina had a beautiful flower-like appearance.—

[33v]

(a) 198

(b) Small as my collection of plants is from the Abrolhos I think it contains nearly every species then flowering.—

(c) This is an instance (perhaps not a strongly marked one) where there is a great formation of Coralls: & therefore the lime obtained without the neighbourhead of Volcanic action.— The currents in the ocean would however I think be sufficient for a ridge like this:—

34

1832 Abrolhos Islands

Gen observ: The Abrolhos Islands seen from a short distance are of a bright green colour.— The vegetation consists of succulent plants & Gramina, interspersed with a few bushes & Cactuses.— (b) Birds of the family of Totipalmes are exceedingly abundant, such as Sulas Gannets, Tropic birds & Frigates.— The number of Saurians is perhaps the most surprising thing, almost every stone has its accompanying lizard: Spiders are in great numbers: likewise rats:— The bottom of the adjoining sea is thickly covered by enormous brain stones; many of them could not be less than a yard in diameter: Without being in the immediate presence of limestones how extraordinary it is that (c) these Polypi should be able to obtain such an enormous stock of Carb of Lime

Parmacella (a) Parmacella (Cuvier) body lengthened; broardest across the mantle.— Mouth labiate with upper lip bilabiate, inferior with a fold.— when closed it is folded into 5 irregular rays: Body beneath pale, above light dirty yellow; with few blueish lead coloured markings; colours more intense under the shell; 2 interrupted blueish lead coloured longitudinal bands on the back.— Shell transparent very brittle, oval, concave posteriorly beaked & slightly spiral; increases by concentric layers.— Lightly attached to the mantle, edges being overlapped by a membrane.—

[34v]

(a) [sketch] The curved lines may represent the ridges or waves in the muscle of the foot; each one travelling onwards after the one before it; a new one of course continually commencing at the tail.— I fancied I perceived a slight contraction after the formation of each wave.—

(b) How naturally does the animal by its habits & organization connect through Succinea the terrestrial Pulmones without a shell, with those with one.—

(c) 199

35

April

1832

Parmacella Tentacula, superior lead coloured, inferior very short.— Length of large specimen 1.4 inch. breadth .4.— Habits, lives on aquatic plants & is partly amphibious.— When placed in water, turns its back downwards, draws in its tentacula & swims slowly till it finds some object to adhere to.— It moves in the same manner in the water as on a solid substance, viz by a wave-like motion in the foot; each wave is semicircular & travels upwards from the very extremity to the head.—

(a) It is not clear how the movement propels the animal.— Is it by a slight contraction after the formation of each wave?

Physa Physa.— shell sinestral.— Animal: foot thin. much separated from body. rounded in front, tail extremely pointed, lead coloured.— Tentacula long, tapering of same colour, with an attached membrane at the base.— Eyes within the base of feelers.— Over the mouth a large inverted wedge shaped bilabiate membrane.— Lives in grassy ditches, swims with its shell downward very rapidly by the aid of front projecting part of foot.— Steers itself by the head, perhaps membranes at base of feelers assist in this.— Body in nearly the same direction as opening of shell; when dead, not perfectly retractile: a fringed membrane projecting from around opening of shell.

[35v]

(a) 435 (not spirits)

(b) 185

(c) 207