809 



MICIPPA. 



MICROPTERUS. 



810 



gneiss, primary limestone, quartz rook, chloritic schist, and clay-slate, 

 and is deficient in organic remains. There are however certain more 

 recent assemblages of strata more or less allied to mica-schist in 

 composition, of very limited area, adjacent to granitic elevations, in 

 Dauphine 1 , &c., which do contain organic remains of the secondary 

 periods. 



To the British geologists the southern Highlands of Scotland and 

 the mountains of Donegal offer abundant and striking examples of 

 mica-schist, with ita associated limestones, quartz rocks, &c., while 

 round the granites of the Isle of Man, Cumbria, Devon, and Cornwall, 

 hardly a trace of gneiss or mica-schist has been observed. 



Mica-schist, in its most typical state differs from gneiss by the 

 absence of felspar, but among the early stratified rocks the gradations 

 and permutations of ingredients are so frequent as to confound all 

 merely mineral distinctions, from hand specimens. The mica is 

 usually spread through the rocks of this series in continuous surfaces 

 overspreading the quartz portions, whereas in gneiss this seldom 

 happens. In respect of the magnitude, relative abundance, and crystal- 

 line aspect of the ingredients of mica-schist, there is every possible 

 variation, so that some specimens approach obscurely to granite, others 

 to well defined gneiss, and others to clay-slate. 



Dr. M'Culloch proposed the following synopsis of Micaceous 

 Schist: 



Division I. Consisting of mica and quartz. 

 Subdivision 1. Simply laminar or foliated. 



a. Composed principally of continuously laminar mica. 

 4. Composed principally of continuously laminar quartz. 



c. The mica discontinuous, the quartz granular. 



d. The mica greenish, approaching to chloritic schist. 



e. Mica gray, approaching to talcose schist. 

 /. Approaching to clay-slate. 



The rocks of this subdivision are frequently and remarkably con- 

 torted. 



Subdivision 2.- Granularly laminar. 



a. Granular quartz, with scales of laminar mica. 

 6. Laminar quartz, with mica in scattered spots. 

 e. Laminar quartz, with distinct scales of mica. 

 d. Laminar quartz, with mica in parallel lines, so as to appear 

 fibrous on splitting. (Aranturine seems to be of this nature.) 

 c. The mica bent and contorted round the grains of quartz. 

 Division II. Compounded of three or more ingredients. 

 a. With hornblende. 

 6. With felspar (passing to gneiss). 



c. With chlorite or talc (passing to talcose or chlorite schist). 



d. With more than one of these ingredients. 



e. With carbonate of lime. 



Division III. -Conglomerated, or containing superadded fragments 

 of granite, gneiss, limestone, &c. It occurs in Isla, Garveloch, llau- 

 noch, &c. 



Besides the minerals above noticed, many others occur in mica- 

 schist, so as universally to modify its aspect. This is particularly the 

 case with garnet, which is often perfectly crystallised amidst the mass 

 of fragmentary mica and quartz, and is so frequently met with in 

 mica-schist, that it seems to mark a particular condition, through 

 which the rock has passed since its first deposition. 



The circumstance which perhaps more than any other deserves 

 attention in studying these rocks, is the character of their stratification. 

 Where limestones or clay -slates alternate with the mica schist, its strata 

 are easily traced ; but in cases where entire mountains are formed of 

 laminated mica and quartz, the contortions to which the whole is 

 subject render it very difficult to determine the prevalent dip of the 

 beds. 



It is difficult to avoid the belief that the smaller contortions of 

 gneiss and mica-schist are due to causes quite distinct from violent 

 movement ; they are characteristic of a peculiar mode of deposition, 

 ' or marks of a subsequent modifying process. Whether the great con- 

 tortions may be thus explained, or require the supposition of great 

 disturbances of position, is not easy to determine. [GEOLOGY; ROCKS." 



MICIPPA, [MAUD*:.] 



MICO, or Fair Monkey, one of the common names for that species 

 of Oiiintili (Ifapale of Illiger) known to zoologists as the Jacchus argen 

 latui, Geoff., Simia argentata, Linn. It is a very pretty little species. 

 perhaps the prettiest of the genus. [JACCHUS.] The head is small 

 and round, the face and hands of a deep flesh-colour; indeed the face 

 and ears are of so lively a vermilion, that the animal, when in i'ul 

 health, looks almost as if it had been painted with that colour. The 

 body is covered with long silvery-white hair, and the tail is of a shining 

 dark chestnut, sometimes almost black. 



MICHASTERIAS. [DESMIDIBA] 



MICROCE'BUS, M. Geoffrey's name for a form among the Lc- 

 muridie ; Lemw (Oalago) Guineensit. [LiEMuniM:.] 



MICRODACTYLUS. [CABIAMA.] 



MICKOGLOSSUS. [PBITTACIM.} 



MICROLITE. [PTROCHLOB.] 



MICROLOPHUS. [IoUANiDJS.1 



CROPO'GON, M. Temmiuck's name for a genus of Scausoria 



Jirds which has the general structure of Bucco. The gape however 

 s smooth. The first three quills only are graduated. Mr. Swaiuson 



arranges it under the Bucmince, or Barbuts, a sub-family of his 

 "icidce. [Picnwe.] 

 MICRO'PTERUS, a name assigned by Messrs. Quoy and Gaimard to 



a genus of Anatidce, remarkable for the shortness of their wings. 



Two species are recorded, namely: M. brachypterus (Quoy and 

 jraimard, Oidemia Patachonica, King, Aiian brachyptera, Lath., Race- 

 Horse of Cook and Byron, and Steamer-Duck of King), and M . Pata- 



chonicus, King, which is smaller in the body than the first, and is able 



to fly. 



M. brachypteiiis is above lead-colour, inclining to gray; abdomen 



whitish ; the beauty-spot on the wings white, at the bend a blunt spur; 

 aill yellow, the nail blaok ; legs fuscous yellow. Length from tip of 



the bill to end of tail, 40 inches; of bill, 3 inches; of wing, from 



carpel joint to apex of second quill-feather, 11 inches; of tail, 5 inches 



of tarsi, 2| inches. (King.) 



Kaoe-llorse or Steamer-Duck (Microptenu brachypterus). 



Captain Philip Parker King, R.N., who has described both species, 

 one in the ' Zool. Journal,' and the second in the ' Zool. Proceedings,' 

 first fell in with the larger species at Eagle Bay, beyond Cape San 

 Isidro (Point Shut-up of Byron), in the Strait of Magalhaens. "Here," 

 writes Captain King, " we saw, for the first time, that most remarkable 

 bird the Steamer-Duck. Before steam-boats were in general use, this 

 bird was denominated, from its swiftness in skimming over the surface 

 of the water, the Race-Horse, a name which occurs frequently in Cook's, 

 Byron's, and other voyages. It is a gigantic duck, the largest I have 

 met with. It has the lobated hind toe, legs placed far backwards, 

 and other characteristics of the oceanic ducks. The principal pecu- 

 liarity of this bird is the shortness and remarkably small size of the 

 wings, which, not having sufficient power to raise the body, serve only 

 to propel it along, rather than through the water, and are used like 

 the paddles of a steam-vessel. Aided by these and its strong broad- 

 webbea feet, it moves with astonishing velocity. It would not be an 

 exaggeration to state its speed at from 12 to 15 miles an hour. The 

 peculiar form of the wing and the short rigid feathers which cover it, 

 together with the power this bird possesses of remaining a considerable 

 time under water, constitute it a striking link between the genera 

 Anas and Aptenodytes. It has been noticed by many former navi- 

 gators. The largest we found measured 40 inches from the extremity 

 of the bill to that of the tail, and weighed 13 Ibs. ; but Captain Cook 

 mentions, in his second voyage, that the weight of one was 29 Ibs. 

 It is very difficult to kill them, on account of their wariness and thick 

 coat of feathers, which is impenetrable by anything smaller than 

 swan-shot. The flavour of their flesh is so strong and fishy, that at 

 first we killed them solely for specimens. Five or six months however 

 on salt provisions taught many to think such food palatable, and the 

 seamen never lost an opportunity of eating them. I have preferred 

 these ducks to salt beef, but more as a preventive against scurvy than 

 from liking their taste. I am averse to altering names, particularly 

 in natural history, without very good reason ; but in this case I do 

 think the name of Steamer much more appropriate and descriptive 

 of the swift paddling motion of these birds than that of Race-Horse. 

 I believe, too, the name of Steamer is now generally given to it by 

 those who have visited these regions." 



The same author informs us that Pecten vitreus, whose shell is 

 found attached to the leaves of Fucua giyanieus, together with other 



