1157 



UMBER. 



UNAU. 



1158 



ft. umbrella is the size of a crow, colour that of umber ; the male 

 with an occipital crest. It is found generally in Africa, 



Scopus umbrella. 



UMBER, an Ore of Iron and Manganese, employed as a brown pig- 

 ment. It occurs massive, amorphous. Structure earthy. Fracture 

 conchoidal. Soft. Opaque. Dull. Meagre to the touch ; adheres 

 strongly to the tongue, and falls to pieces in water. Colour blackish, 

 reddish, or yellowish-brown. Specific gravity 2'206. It occurs in 

 beds with brown jasper, in the Isle of Cyprus. It consists of iron, 

 manganese, silica, alumina, and water. 



UMBILI'CUS. When the inner sides of the whorls or volutions of 

 a spiral shell do not touch each other, so that its axis is hollow, that 

 hollow is tt-rmed the Umbilicus. [THOCHID.E; TUHBINID.E.] 



UMBILICUS, a genus of Plants belonging to the natural order 

 Cranulacea. It has a 5-parted calyx ; corolla gamopetalous, campa- 

 uulate, 5-clef t ; lobes ovate, acute, erect, about the length of the tube ; 

 stamens 10, inserted in the corolla; scales 5, obtuse ; carpels 5, atten- 

 uated at the apex ; styles subulate. The species are herbs, indigenous 

 to the soutli of Europe and the Levant. The leaves are rosulate or 

 alternate, quite entire, or a little toothed. The flowers white or 

 yellow, in branched or simple terminal racemes, never in cymes. 

 There are about 17 species. They grow chiefly on rock-work and on 

 old walls. V. tpintant and U. teucantha are natives of Siberia. Some 

 of the species are British, and still remain in the old genus Cotyledon, 

 out of which the genus i'mbilicu has been formed. U. erectus is the 

 Cotyledon i'mbilictu of Linnams, and is described under that genus. 



[COTTLEDOS.] 



UMBO (Conchology), the name for that point in a conchifer or 

 bivalve shell which constitutes the nucleus or apex of each valve, and 

 which is generally situated above the hinge, and always near it. 



[COXCHIFKKA.] 



UMBRELLA. [SKMIFHYLUDIA.] 



UNAU (CholfFpue), n genus of Edentate Animals inhabiting America. 

 The position of this animal with the other forms of the Tardigrade 

 Jidenlala will be seen in the following conspectus [BRAin'i'L's], drawn 

 up by Professor Owen, and published in his work on the ' Osteology, 

 Natural Affinities, and probable Habits of the Megatheroid Quadrupeds 

 in gsneral' : 



Conspectus of the Families, Genera, and Species of the 



Leaf-Eating liruta, 



Order Bruta, Linn., Fisch. (Edentata, Cuv.). 



Teeth none, or wanting a neck and enamel. Claws falculate, great, 

 generally sheathed, bending downwards. 



Tribe Phyllophaga (Leaf-Eaters). 



Teeth few, composed of vascular dentine, hard dentine, and cement; 

 the vascular dentine forming the great axis of the teeth. A descending 

 apophysii in the jugal bone. The acromion concrete with the coracoid 

 process. 



Family I. Tardigrada (Syn. Scamoria, Jlmdypodida). Feet long, 

 (lender, the anterior more or leas longer than the posterior ; fore feet 

 li ur tri-cliictylf, hind feet tridactyle ; toes obvolute, falculate. 

 Zygomatic rch open. Tail very short. 



Genus 1. Bradypus, Linn., 111. (Acheus, F. Cuv.). 

 Genus 2. Cholcepus, 111. (Bradypus, F. Cuv.). 



Family II. Gravigrada (Eradicatoria, Megatheriida). Feet short, 

 very strong, equal or aubequal ; fore feet penta- or tetra-dactyle ; one 

 or two of the external toes unarmed, fit for support and progression ; 

 the rest falculate. Zygoniatic arch closed. Clavicles perfect. Tail 

 moderate, stout, and acting as a fulcrum or prop. 



Genus 1. Meyalony.r, Jefferson, Cuv. (Megatherium, Desni., Fisch.).- - 



Teeth ^ ' sub..-lliptical, the middle of the crown excavated, the 

 4 4 i 



margins slightly prominent. Fore legs the longest; the tibia and 

 fibula distinct ; the heel-bone long, compressed, and deep ; the falculai 1 

 claws great and compressed. 



Species, At. Jeffersoni, Cuv. (Megatherium Jeffersonl, Desm., Fisch. ; 

 Mcgalonyx laqueatus, Harlan). 



Genus 2. Megatherium, Cuv. (Bradypus, Pander and D' Alton). 



5 5 

 Teeth ^ ? , contiguous, tetragonal, the crown transversely suloated. 



The fore feet tetradactyle ; the hind feet tridactyle, the two external 

 toes unarmed ; the falcular claws great and diversiform; those of the 

 middle toe greatest, and compressed. Femur with an entire (unim- 

 pressed) head ; tibia concrete, with the fibula at each extremity. 

 Astragalus with the anterior face excavated above. Heel-bone long 

 and thick. 



Species, M. Cuvieri, Desm. (Bradypui giganteut, Pander and 

 D' Alton). 



Genus 3. Mylodon, Owen (Mcgalonyx, Harlan ; Orycterothcrium, 



Harlan). Teeth . , distinct; the anterior upper tooth subelliptical, 



4 4 



moderately remote from the rest ; the second elliptical ; the rest tri- 

 gonal, with the internal face longitudinally sulcated ; the anterior 

 lower tooth elliptical, the penultimate tetragonal ; the last, which is 

 the greatest, bilobate. Feet equal : fore feet pentadactyle ; hind feet 

 tetradactyle ; the two external toes in both unarmed, the rest falcu- 

 late ; the falcular claws great, semiconical, and unequal. Head of the 

 femur impressed by the round ligament ; tibia and fibula distinct ; 

 astragalus with anterior face flattened above ; heel-bone long and thick. 



Species 1, If. Darwinii, Owen. The lower jaw with the symphysis 

 longer and narrower; the second molar subelliptical; the last bisul- 

 cate, the internal furrow angular. 



Species 2, M. JIarlani, Owen (Megalonyx laqueatus, Harlau ; Oryctc- 

 rotheritun Missouriense, Harlan). Lower jaw with a shorter and wider 

 symphysis; second molar subquadrate; the last trisulcate, the internal 

 furrow biangular. 



Species 3, M. rubualus, Owen. Lower jaw with the symphysis 

 shorter and wider ; second molar subtrigoual ; the last trisulcate, the 

 internal furrow rounded. 



Genus 4. SceHdotherium, Owen (Meyalonyx, Lund). Teeth nf, 



4 4 



either contiguous or separated by equal intervals ; upper ones trigo- 

 nal ; the anterior of the lower ones trigonal, the second and third 

 subcompressed, the external face longitudinally sulcated ; the last the 

 greatest and bilobate. Head of the femur impressed by the ligamcn- 

 turn teres ; tibia and fibula distinct ; astragalus with two excavations 

 anteriorly. Heel-bone long, thick ; falcular claw great and semi- 

 conical. 



Unau (0/iolapiu). (Do Blainville.) 



Species, >S'. leptocephalum, Owen ; .S'. Cuvieri, Owen (M. Cuvieri, 

 Lund) ; & Bucklandi, Owen (M. Bucklandi, Lund) ; 8, miniitum, 

 Owen (M. minutus, Lund). 



Genus 5. Calodon, Lund. Teeth -^-. 



33 

 Genus G. Sphienodon, Lund, 



