(R. Br.)

(Desc. by Schiu., in Walp. Repert., ii, 925, 1843, under E. angulcsa, and by Mueller under Brown's name. Trans. Vic. Inst., 3854, 33, and recently by Luehmann, Vic. Nat., vol. xiii, p. 147, 1897, under the name of E. torquata.)

Systematic. - A small tree, reaching a height of 20 to 30 feet, with a rough bark. Leaves lanceolate to broad lanceolate, acuminate, often uncinate, thick, coriaceous and shining, usually under 5 inches long; venation very indistinct, except in the young foliage, when the vascular bundles are marked by grooves on the leaf surface, intramarginal vein removed from the edge, lateral veins more or less spreading, inclined at about 300 to the mid-rib. Peduncles axillary or lateral, flattened, about 9 lines long, each bearing an umbel of three to seven flowers. Buds shining, with seven to ten ridges, shortly pedicellate; calyx tube urn- or bell-shaped, 4 to 5 lines long; operculum 4 lines long, at first domed and slightly greater in diameter than the calyx, in some cases the upper half abruptly contracted into a narrow cone.

Fruit.- Truncate-ovoid, inclined to be urn-shaped, more or less longitudinally ribbed, shining; rim convex, the periphery concave due to the prominent groove; valves not ex-serted; from 5 to 10 lines long and 4 to 7 lines in diameter at the widest part.

A very characteristic fruit and one which has little resemblance to E. incrassata of Western Australia, although it has sometimes been confounded with it, the pronounced ribs readily distinguishing the two species.

Habitat. - Victoria, South Australia and Western Australia (Coolgardie, Luehmann), and South West of New South Wales.

REMARKS. - The specimens which have come under our notice, and the published localities of others, show that this species has a wide range, and it would appear now that it has been recorded under several specific names We have given the authorship to Robert Brown, who collected and gave it the name E. costata, although Schaier described it later, '843, under E. angulosa. Mueller described it, 1854, Trans. Vict. Inst., p. 53, under Brown's name. The smaller fruited variety was described by Luehmann under the name of E. torquata. Vic. Nat., vol. xiii p. 147, 1897. To add to the confusion the whole of these have been regarded as E. incrassata and its varieties, whilst the material collected by Labillardiere and F, v. Mueller in Western Australia prove that E. costata is not that species,

ESSENTIAL OIL. - Leaves and terminal branchlets of this species for distillation were forwarded by Mr. Walter Gill, the Conservator of Forests, South Australia. The material was collected at the Parilla Forest Reserve, of that State, in October, 1919. The yield of oil was 0.9 per cent.

The crude oil was red in colour and had an odour resembling the cineol-pinene oils generally. The constituents present were dextro-rotatory pinene, cineol, alcoholic bodies, a small amount of esters and a little sesquiterpene. Phellandrene was absent, and eudesmol not detected.

The crude oil had specific gravity at 150 C. = 0.9216; rotation aD + 4.8°; refractive index at 200 C. = 1.4657, and was soluble in 1.2 volume 70 per cent, alcohol. The saponification number for the esters and free acid was 4.5. After acetylation it was 36.9, and in the cold with two hours' contact it was 27.

On rectification, 2 per cent, distilled below 1650 C. (corr.). Between 165-1710, 18 per cent, distilled; between 171-1930, 67 per cent came over; between 193-2350, 5 per cent. distilled, and between 235-2670, 7 per cent. These fractions gave the following results: -

These results closely approximate to those of E. calycogona, with the exception that the latter contained a little more pinene and consequently less cineol.

The cineol was determined by the resorcinol method in the portion distilling between 165-1930 C, and calculated for the crude oil; the result was 67 per cent. By the phosphoric acid method it was 57 per cent. when calculated for the crude oil.

Material of the large fruited variety was also received for distillation from Mr. Walter Gill, the Conservator of Forests of South Australia. It had been collected on the West Coast of that State, in the Port Lincoln District, in April, 1920.

The yield of oil was 1.2 per cent. The crude oil was red in colour and had an odour similar to those belonging to the cineol-pinene groups of Eucalyptus oils. The constituents present were dextro-rotatory pinene, cineol, alcoholic bodies, a small amount of esters, and come sesquiterpene. Phellandrene and aromadendral were not present, nor was crystallised eudesmol detected. The results with the oil of this form show it to agree with that of the small fruited variety, with the exception that the pinene was more abundant and the cineol correspondingly less in amount, which may be accounted for by the difference in the time of the year.

The crude oil had specific gravity at 150 C. = 0.9023; rotation aD + 11.8°; refractive index at 200 - 1.4676, and was soluble in 1 volume 80 per cent. alcohol. The saponification number for the esters and free acid was 5.8 by heating, and 5.2 in the cold, with two hours' contact.

After acetylation the saponification number was 3625 by heating, and 22.34 in the cold, These results agree with the above.

Plate XLII.

The dry country habitat of this species is indicated by the large number of oil glands seen in the two cross sections of the leaves. In this case nature has evidently responded to the physical conditions obtaining in the home of this Eucalyptus, and being so provided can by the volatilisation of the essential oil surround itself during excessive heat by a perfume medium and, by warding off the solar heat rays, reduce transpiration and so live on when other plants less favoured by nature to resist heat, perish. The short red bands in the middle of the sections show the large number of vascular bundles present (cut more or less obliquely). The sunken stomata are also a feature of this species. x 40.

Eucalyptus Costata. R.Br

On rectification, 1 per cent. distilled below 162° C. (corr.). Between 162-1730, 5 per cent. distilled; between 173-193°, 36 per cent. came over, and between 193-276°, 10 per cent. distilled. These fractions gave the following results: -

The cineol was determined by the rapid phosphoric acid method in the crude oil; the result was 35 per cent.