693 



MAGNESIA. 



69 1 



grains of allowance. The singing is not corroborated by subsequent 

 observers. 



Mr. Caley informed Mr. Vigor?, that from the observations he wag 

 enabled to make on these birds during his stay in Australia, it was 

 his opinion that they were gallinaceous. Mr. Caley generalK found 

 them in flocks, and for the most part on the ground. M. Lesson 

 states that they come forth in the evening and the morning, remaining 

 quiet during the day on the trees whereon they perch. He says that 

 they are becoming more and more rare, and that he only saw two 

 skins during the whole of his stay at New South Wales. Mr. Swainson 

 informs us that chief-justice Field, of Gibraltar, who was long a 

 resident in Australia, assured him (Mr. S.) that Mcmura in all its habits 

 was a gallinaceous bird, living on the ground in small societies, and 

 being very fond of rolling in the dust. 



Mr. Bennett, in his ' Wanderings in New South Wales,' &c., remarks 

 that this Native Wood-Pheasant, or Lyre-Bird of the colonists, the 

 Be'leck-Beleck and Balangara of the aboriginal tribes, is abundant 

 about the mountain ranges in all parts of the colony. The tail-feathers 

 are detached entire from the bird, and are sold in the shops at Sydney 

 in pairs. Mr. Bennett observes that the price was formerly low ; but, 

 now- that the bird, from continued destruction, has become rare, their 

 tails fetch from 20j. to 30*. the pair. About the ranges however of 

 the Tuinat country, where they have been seldom destroyed, they are 

 more frequently seen. 



The same author states that it has its young in December, the 

 season when all th? wild animals in the colony are produced, and can bo 

 then procured with facility. " It is," says Mr. Bennett in continuation, 

 " a bird of heavy flight, but swift of foot. On catching a glimpse of 

 the sportsman it runs with rapidity, aided by the wings in getting 

 over logs of wood, rocks, or any obstruction to its progress ; it seldom 

 flies into trees, except to roost, and then rises only from branch to 

 branch : they build in old hollow trunks of trees which are lying upon 

 the ground, or in the holes of rocks ; the nest is formed merely of 

 dried grass or dried leaves scraped together. The female lays from 

 twelve to sixteen eggs of a white colour, with a few scattered blue 

 spots. The young are difficult to catch, as they run with rapidity, con- 

 cealing themselves among the rocks and bushes. The Lyre-Pheasant, 

 on descending from high trees on which it perches, has been seen to 

 fly some distance. It is more often observed during the early hours 

 of the morning, and in the evenings, than during the heat of the day. 

 Like all the gallinaceous tribe, it scratches about the ground and 

 roots of trees to pick up seeds, insects, &c. The aborigines decorate 

 their greasy locks, in addition to the emu feathers, with the splendid 

 tail-feathers of this bird, when they can procure them." 



Mr. Bennett laments the rapid disappearance of the races of animals 

 found in a new country, and which are pursued, whether useful or 

 dangerous, even to extermination. He states that in the settled parts 

 of the colony the harmless kangaroos and emus are rarely seen, when 

 they might easily be domesticated about the habitations. " The same 

 remark," he adds, "applies to the Lyre-Pheasant. Why are they 

 not domesticated, before, by extermination, they are lost to us for 

 ever?" 



M^ERA, Dr. Leach's name for a genus of Amphipodous Crustacea. 

 M. yrostnmana, Leach (Cancer Gammarus yrossimanus, Montagu) ' Linn. 

 Trans.,' ix. tab. 4, fig. 5, is very common on the English coasts, where 

 it is found \inder stones and rooks at low water. 



MAGI'LUS, De Montfort's name for a genus of Testaceous Mollusca, 

 the form of whose shell varies very much according to its different 

 stages of growth and the circumstances in which it is placed. 



The genus was placed by Lamarck among his Annelida, in the 

 family Serpulacea, containing the genera Spvrorbis, Serpula, Vtrmilia, 

 Galeoiaria, besides that under consideration. 



M. De Blainville arranged it among the Mollusca (family Cricoito- 

 maJa), between Siliquaria and Valvata, observing at the same time 

 that Guettard clearly saw the relation of the form to Vermetta. 



Cuvier, in his last edition of the ' Regne Animal,' gives it a position 

 between Verme'iu and Siliquaria, in his seventh order of Gastropods 

 ( Titbulibranchiata). 



M. Rang remarks that, when he was seeking the animal in India, he 

 was struck, like M. De Blainville, with the analogy which the genus 

 presents not only to Vermetus, but also to many other genera of 

 Pectinibranchiata. This analogy, M. Rang further observes, is espe- 

 cially remarkable when a young individual whose shell has not yet 

 become tubular is examined. 



M. Rang states that he saw some fragments of the animal, and that 

 it is certainly a Gastropod. In his descrip- 

 tion however he notes the animal as unknown. 

 Dr. Kupprll states that it is furnished with 

 an operculuin. 



Hhell. Young: Fragile, with an epidermis, 

 pyrifonn, ventricose, with a short spire of 

 from three to four turns; aperture longer 

 than it is wide, oblong, without any notch 

 anteriorly, where the lip nevertheless forms 

 an angle. Dr. Ruppell thinks that M. Rang, 

 when he wrote the above description, had 

 before him the young of Leptoconchus. shc " of 



(young). 



Adult : The last whorl abandoning altogether the spiral form to 

 HAT. HLJT. DIV. VOL. III. 



produce an elongated tube, which is irregularly sinuous, or irregularly 

 contorted, conical, compressed laterally, especially on the side of the 

 base of the shell, carinated beneath, and free ; aperture elliptical. 



Shell olMagilus (old). 



When in this state the shell presents all the characters of a regularlv 

 spiral univalve. The animal establishes itself in the excavations of 

 Madrepores (Astrasas, &c.), and as the coral increases around it the 

 Mayilui is obliged, in order to have its aperture on a level with the 

 surrounding surface, or near it, to construct a tube, which is more or 

 less eccentric according to circumstances, the growth of the coral 

 determining the length of the tube. As this tube goes on increasing 

 the animal abandons the spiral for the tubular part of the shell, and 

 in this operation it leaves behind no septa, or partitions, but secretes 

 a compact calcareous matter which reaches to the'very summit of the 

 spiral part, and is deposited from time to time as the tube is length- 

 ened ; so that in an old specimen the posterior part of the shell presents 

 a solid and almost crystalline mass : indeed the fracture of this mass 

 is radiated and saccharoid. One species only, Mayilus antiquvs, is 

 known. The colour is white, more or less pure. [LEFTOCONCHUS.] 



MAGNESIA, the Oxide of the metal Magnesium. Magnesia, as 

 well as several of its salts, occur as minerals. The sulphate and 

 nitrates of magnesia are soluble, and have a bitter taste. The other 

 native salts are insoluble. The specific gravity of all the salts is 

 below 3. 



Shepbardite, also called Brucite, is a hydrate of magnesia. It occurs 

 rarely, in hexagonal prisms, generally in laminar masses, and fibrous. 

 Its primary form is a rhomboid. Colour white, greenish-white. Streak 

 white. Lustre pearly. Transparent, translucent. Hardness I'O to 

 1-5. Specific gravity 2'33 to 2'63. It is found at Hoboken, in New 

 Jersey, North America, and in the island of Unst, Shetland. Bruce, 

 after whom it has been named, gives as its composition 



Magnesia 70 



Water 30 



100 



Nemalite is a name given to a fibrous form which contains some 

 iron and carbonic acid. It occurs with the first form in North 

 America. 



Sulphate of Magnesia is the well-known Epsom Salts. It is often 

 found in solution in mineral springs, also in sea-water. In some 

 places it has been found crystallised. At Helderberg it occurs as an 

 efflorescence, and it is called Hair-Salt. [ErsoMITE.] 



Magnetite, Carbonate of Magnesia, occurs in acicular crystals, 

 massive, and in powder. Its colour is usually white, occasionally 

 grayish and yellowish. The massive varieties are found amorphous, 

 reniform, nodular, and stalactitic. Fracture splintery, or flat con- 

 choidal. Its hardness exceeds that of calc-spar. It is dull, nearly 

 opaque. Specific gravity 2'8. It is found in several parts of Europe, 

 as Styria, Moravia, Spain, and Silesia, in India, and at Hoboken, iu 

 New Jersey, North America. Its analysis by Rauimelsberg gives 



Carbonic Acid 52'214 



Magnesia . 47786 



100 



