MILNESIUM. 



[ 505 ] 



MNIOIDE.E. 



heat. It gives a red colour to certain sub- 

 stances, gently boiled in it. 



The following substances and tissues are 

 coloured red by the test : albumen, caseine, 

 chondrine, crystalline, epidermis, feathers, 

 fibrine, gelatine, gluten, horn, legumine, 

 proteine, silk, wool. 



The following, when pure, are not co- 

 loured : cellulose, chitine, cotton, gum (ara- 

 bic), linen and starch. 



BIBL. Millon, Compt. Rend. 1849, or 

 Chem. Gaz. 1849, vii. 87. 



MILNE'SIUM, Doyere. A genus of 

 Arachnida, of the order Tardigrada (Colo- 



". Head with two very short palpi- 

 form appendages at its anterior and lateral 

 parts ; mouth terminated by a sucker sur- 

 rounded by palps ; skin soft, transversely 

 furrowed ; legs four pairs ; rings of the body 

 divided into two segments. 



M. tardigradum (PI. 50. fig. 9). Mouth 

 surrounded by six minute unequal palpi, 

 symmetrically arranged, diminishing in size 

 from the upper to the lower part; head 

 rounded in front when the mouth is re- 

 tracted ; eye-spots tolerably large and gra- 

 nular; pharyngeal tube much dilated, styles 

 very small, bulb elongated and pvriform, 

 without an internal framework ; body trans- 

 parent, attenuated at both ends, especially 

 the posterior ; skin pale brownish yellow ; 

 three anterior pairs of legs nearly equal, the 

 fourth very short, resembling two tubercles, 

 with scarcely a trace of annuliform division ; 

 claws four, two terminal, and in the form of 

 elongated filaments hooked at the end, and 

 each supported on a distinct tubercle ; two 

 inferior and internal, the anterior divided 

 into three strongly curved hooks, the pos- 

 terior into two ; hooks or terminal filaments 

 of the fourth pair longer than those of the 

 first three. Movement active. Length 

 1-50 to 1-40". 



BIBL. Doyere, Ann. Sc. Nat. 



MIMOSEL'LA, Hincks. A genus of 

 Ctenostomatous Polyzoa, fam. Vesiculariidae. 



Char. Zoary confervoid, jointed, and 

 branched ; cell's ovate, opposite, with a basal 

 joint; animals with eight tentacles and a 

 gizzard. 



M. gracilis. Branches erect, arising from 

 a creeping fibre. On sea-weeds. 



BIBL. Hincks, Polyz. 555. 



MINERALOGY, APPLICATION OF THE 

 MICROSCOPE TO. The following substances 

 may be recognized in transparent minerals 

 or blowpipe beads, by means of the cha- 



racteristic absorption-bands seen in the 

 spectrum, even when they are much co- 

 loured by the oxides of iron, manganese, or 

 nickel, viz. didymium, erbium, uranium, 

 cobalt, chromium, copper, manganese, and 

 jargonia. In one method the substance is 

 fused with borax or microcosmic salt, so as 

 to give a clear bead, and the spectrum is 

 examined by means of the spectrum eye- 

 piece. In the other method, the saturated 

 borax bead is kept hot over the lamp, so 

 that crystals may be deposited in it. Many 

 kinds of crystals may be thus distinguished. 

 See SPECTROSCOPE and ROCKS. 



BIBL. Sorby, Qu. Mic. Jn. 1869, 182. 



MIRROR OF SCEMMERING. See 

 INTRODUCTION, p. xxii. 



MISCHOCOC'CUS, Nag. A genus of 

 Palmellacese. 



Char. Thallus gelatinous, branched ; the 

 terminal cells of the branchlets in pairs or 

 fours. In boggy pools. 



M. confervicola (PI. 52. fig. 12). 



BIBL. 'Rabenht. Fl. Alg. Eur. iii. p. 54. 



MISTLETOE. See VISCUM. 



MITES. The animals usually included 

 under this term are species of Acarina. 



MITOPH 'ORA, Perty A genus of Cilio- 

 Flagellate Infusoria. Free, ovate, with"fc 

 lateral row of parallel stout cilia, and a long 

 terminal flageHum. M. dubia, freshwater. 

 (Perty, Lebens. 153.) 



MNIA'CE^E. A tribe of Mnioide 

 (Mosses), of Bryoid habit, but with firm, 

 rigid, and usually undulated leaves, mostly 

 increasing in size toward the top of the 

 stem. British genera: Cinclidium, Geor- 

 gia, Mnium, and Timmia. 



MNIADELPHA'CE^E. A family of 

 Pleurocarpous Mosses, with the leaves ar- 

 ranged in four or more series, and composed 

 of parenchymatous cells, mostly equally 

 hexagonal and Mnioid, very smooth, pellu- 

 cid, destitute of a distinct primordial utricle, 

 the lowest decurrent on the stem at the base, 

 larger, spongy, lax, mostly beautifully dark- 

 tinged, never single, slender. Brit, genus : 



DaUonia. Calyptra mitre-shaped, bell- 

 shaped, elegantly fringed at the base. Pe- 

 ristome double (Neckeroid) : outer, sixteen 

 narrow, subulate, trabeculate teeth, reflexed 

 when moistened ; inner, an equal number 

 of similar cilia, alternating with the teeth, 

 devoid of a basilar membrane. 



MNIOI'DE^E. A family of operculate 

 Mosses, ordinarily of acrocarpous habit, but 

 sometimes pleurocarpous, with broadly oval, 

 spathulate, ov4 or lanceolate, flattish leaves, 



