MUR 



MUS 



MU'RCHISONITE. A variety of 

 moonstone or felspar, occurring in the 

 new red sandstone, in the neighbourhood 

 of Davvlish. 



^ MURE'XIDE {murex, a molluscous 

 animal yielding a purple dye). A beau- 

 tiful purple product of the decomposition 

 of uric acid, first described by Dr. Prout 

 as purpurate of ammonia. Murexan is 

 the purpuric acid of Prout. 



MU'RI ACITE. Anhydrous sulphate of 

 lime, also called anhydrite and cube-spary 

 occurring crystalline, fibrous, granular, 

 and compact. To the last of these belong 

 some of the Italian varieties known by 

 the names of bardiglio and hardiglione, 

 as also the singular fibrous-compact 

 variety familiarly called tripe-stone {^xexxe 

 des trippes), from the salt mines of Wie- 



MURIATE or HYDROCHLORATE. 

 A salt formed by the combination of mu- 

 riatic or hydrochloric acid. Metallic muri- 

 ates which contain an excess of acid 

 are called oxy-muriates ; those in which 

 there is a deficiency of acid, are named 

 sub-muriates. 



MURIA'TIC ACID {muria, brine). 

 Hydrochloric acid. An acid consisting 

 of chlorine and hydrogen, and contained 

 in great abundance in sea-water, in com- 

 bination with soda and magnesia. Oxy- 

 genated muriatic acid is another name 

 for chlorine. 



MURICA'LCITE. Another name for 

 rhomb-spar, a mineral consisting of the 

 carbonates of lime and magnesia. It is 

 also called bitter-spar. 



MURI'CIDiE. The Murexes and 

 Whelks ; a family of carnivorous Gaste- 

 ropods, having the respiratory siphon in 

 general very much developed, and its 

 corresponding canal at the base of the 

 shell always straight. 



MURICI'N.^. Murexes ; a sub-family 

 of the Muricidae, named from the typical 

 genus murex, and sometimes called rock- 

 shells, from the roughness and irregula- 

 rity of their surface. 



MU'RID^ {mus, a mouse). The Rat 

 tribe; a family of the Rodentia, con- 

 taining the smallest and the most nume- 

 rous species of the Mammalia. 



MU'RI DE (muria, brine). The name 

 first given to bromine, from its being an 

 ingredient of sea- water. 



MU'RIFORM {murus, a wall, forma, 

 likeness). Wall-like ; a term applied to 

 the tissue constituting the medullary 

 rays in plants, from its presenting an ap- 

 pearance similar to that of bricks in a wall. 

 228 



MU'SCA. The Fly; a modern northern 

 constellation, consisting of six stars, 

 situated between Crux and the South Pole. 



MU'SCHELKALK {muschel, a shell, 

 kalk, lime). A limestone, belonging to 

 the Upper New Red Sandstone group. 

 Its position is between the Magnesian 

 Limestone and the Lias. This formation 

 has not yet been found in England, and 

 the German name is adopted by English 

 geologists, 



MUSCI. The Moss tribe of Acotyle- 

 donous plants. CeWnlax, flowerless plants, 

 with leaves imbricated, entire, or ser- 

 rated ; reproductive organs either axil- 

 lary bodies containing spherical or oval 

 particles, emitted on the application of 

 water, or thecce, seated on a seta or 

 stalk. 



MUSCICA'PID^ [muscicapa, the fly- 

 catcher). Myiotherincs. The Fly-catchers; 

 a family of the Insessores, or Perching 

 birds, characterized by the peculiar form 

 of the bill, with the strong bristles at its 

 base, and by the small size of the feet. 

 See Dentirostres. 



MUSCID^ {musca, a fly). The Fly 

 tribe ; a family of Dipterous insects, be- 

 longing to the sub-section Athericera, 

 readily distinguished by their strong gene- 

 ral resemblance one to another. Their 

 larvae are known as maggots. 



MUSCOVY GLASS. Another name 

 for mica, most of the commercial article 

 being brought from Siberia, where it is 

 used for window-glass. 



MUSCULAR IMPRESSIONS. A 

 term applied to those indented marks in 

 acephalous bivalves, which indicate the 

 insertion of those muscles by which the 

 animal is attached to its shell. Of these 

 there are three principal varieties • — 



1. The lateral impressions, which de- 

 note that the animal has two adductor 

 muscles, as in unio cardium, and all the 

 most typical bivalves. 



2. The central impression, which de- 

 notes the presence of only one adductor 

 muscle, which is generally in the middle 

 of the shell, as in the oyster. 



3. The pallial impression, which oc- 

 curs in all these shells, and is indicated 

 by a depressed line, often sinuated, run- 

 ning parallel with the ventral margin. 



MUSICAL SOUND. A successioh of 

 sounds which follow one another with 

 such regularity as to produce the impres- 

 sion of a single sound. 



MUSOPHA'GIDiE. The Plantain- 

 eaters ; a family of birds intermediate 

 between the Finches and the Hombills, 



