MOCO. 



MOLLUSCA. 



HI 



MOCO. [ 



MOCKING BIRD. [MINUS.] 



MODIOLA. [MTTIUDJLJ 



MOEHRINGIA, a genus of Plant* named after Paul Henry Gerard 

 Moehring, a German physician, author of ' Hortua Propriu*,' and other 

 work*. ThU genus belong! to the natural order Caryupkytlacetr, and 

 baa 5 sepals, 4 or 5 petal*, either entire or slightly emarginate ; 8 to 

 10 stamens, 2 or S styles, the capsule opening with 4 or 6 valve* ; the 

 weds numerous, with an appendage at the hilum. The species are 

 alpine plant* with the habit of A rawirio. 



if. fruMrrta has ovate-acute stalked 3-5-nerved leaves, the upper 

 ones sessile, the petals shorter than the calyx, the sepals lanceolate- 

 acute, 3-ribbed ; the intermediate rib strongest and rough. This plant 

 was formerly referred to Artnaria, but it may be distinguished from 

 that genus by the appendage to the hilum of the seed. ThU plant is 

 found in damp shady places, and is a native of Great Britain. Four 

 other species of this genus are described by Koch in his ' Flora Germa- 

 nica;' H. muicoia, M. prona, M. polygonoida. and M. rillota. 



The species are alpine plants, and adapted for cultivation on rock- 

 work or in small pots. They may be propagated by dividing them 

 at the root They are best growu in pots, in a mixture of sand, loam, 

 and peat. 



(Babington, Manual of Britith Botany ; Don, Dichtamydeotu Planlt.) 



MOENCHIA, a genus of Plants named after Conrad Moench, pro- 

 fessor of botany at Marburg, who wrote several works on botany ; 

 amongst others, 'Enumeratio Plantarum Indigenarum Hessisc, pne- 

 sertim Inferior!*,' Cassel, 1777, 8vo ; also a work on the cultivation of 

 North American forest-trees in Germany. 



The genus Moenchia belongs to the natural order Caryophyllactce, 

 and has 4 erect sepals, 4 entire petals, 4 stamens, a many-seeded 

 capsule opening at the end with 8 teeth. 



M. ertcla is the only British species. It is a small glaucous plant 

 growing in dry gravelly and sandy places. 



(Bubington, Manual of Brituk Botany.) 



MOHOLL [LEMIRID.K.] 



MOHR [ASTILOPKJS.] 



MOHSITE, a Mineral, consisting of Titaniate of Iron. It occurs 

 crystallised. The primary from is a rhomboid. The crystals occur 

 attached and macled. The cleavage is not observable. The fracture 

 is conchoidal. The hardness is sufficient to scratch glass. The colour 

 and streak are black. The lustre metallic. It is opaque ; not attracted 

 by the magnet. It is found in Dauphiuy. 



MOLASSES. [SUGAR.] 



MOLE. [TALPIDJK.] ' 



MOLE-BAT. [OBTHAOOBI8CCS.] 



MOLE-CRICKET. 

 MOLE-RAT. .. 



MOLENESIA, a genus of Fishes belouing to the lamily 

 The specie* are American. 

 MOLOE. [AMPHIBIA.] 



MOLGULA. ITL-SICAT*,] 



MOLI'NIA, a genus of Grasses belonging to the tribe Patucinetc. 

 It ha* unequal glumes without lateral ribs, shorter than the lanceolate 

 spikelet, of 2 or 3 semicylindrical flowers and a subulate rudiment of 

 another; the paleto hardening on the loose fruit, and the stylos 

 terminal. There is one species which U British 



.'/. cftrulea, which has an erect elongate narrow panicle ; spikolets 

 from 1- to 3-flowered; the outer paleao 3- rarely 5-nerved, downle&s; 

 the upper part of the stem naked. The leaves are long, linear, and 

 alternated. It grows on wet heaths in alpine situations. ThU species 

 U the M. depauperate of Lindley. 



(Rabington, Manual of Brilith Botany.) 



MOLLUSCA. Referring to the articles COXCHIFKRA, GASTEROPODA, 

 CEPHALOPODA, and MALACOLOGY, for information as to the zoological 

 arrangement and subdivision of the various families of the MMutca, we 

 shall in the present article consider the animals which constitute this 

 great group in a purely anatomical and morphological point of view ; 

 that is, we shall endeavour to show firstly, what Common Plan or 

 Archetype is discoverable among the varieties of Molluscan forms ; 

 secondly, in what way the Common Plan is more specially modified 

 in the leading sub-typical groups of this great divUion of the animal 

 kingdom ; thirdly, the various modes in which the organs are arranged 

 being thus comprehended what peculiar characters are presented by 

 the** organ* themselves; and fourthly, the development of the M oilmen, 

 so far as it bean upon the idea of a Common Plan, will bo discussed. 



1. Tke Common Plan or Archetype of '.he Molliuca. By the 

 Common Plan or Archetype of a group of animals we understand 

 nothing more than a diagram, embodying all the organs and ports 

 which are found in the group, in such a relative position as they 

 would have, if none had attained an excessive development. It U, 

 in fact, simply a contrivance for rendering more distinctly compre- 

 hensible the most general propositions which can be enunciated with 

 regard to the group, and ha* the same relation to such propositions as 

 the diagrams of a work on mechanics have to actual machinery, or 

 tboM of a geometrical work to actual line* and figure*. We are 

 particularly desirous to indicate the sense in which such phrases as 

 Archetype and Common Plan are here used ; as a very injurious 

 realism a sort of notion that an Archetype U itself an entity 



appears to have made it* way into more than one valuable anatomical 

 work. It is for this reason that if the term Archetype had not so 

 high authority for it* use, we should prefer the phrase 'Common 

 Plan ' as less likely to mislead. 



There are two modes in which the Archetype or Common Plan of 

 any group of niml. may be set forth. In the first, the community 

 of plan among the members of each group would be demonstrated ; 

 and then, the minor plans thus obtained being compared together, 

 tha general Common Plan would be deducible. But this analytical 

 method (which has been carried out to a certain extent for the Mvlliuca 

 by the writer in a Memoir in the ' Philosophical Transaction* ' for 

 1852), would require more space and more illustration than can here 

 be devoted to it ; we must, therefore, take the opposite course, and, 

 assuming a Common Plan, trace out it* modifications in the sub- 

 ordinate plans, and explain the laws by whose operation they are 

 Jhatad. 



ThU assumed Common Plan or Archetype of the Mulliaca may 

 be represented byfiy. 1, L : 



III. 



IV. 



v. 



> i> 



I. The Ideal Archetype or Common Plan of the ifolliuca. 



II. lt modifications In consequence of the development of an abdomen and 

 consequent neural flexure of the intestine. 1, Hypothetical; 1, I'tcropod ; 

 3, Cephslopod. 



III. Modifications resulting from the development of a post abdomen and con. 

 sequent heinal flexure. I, Hypothetic*!; 2, I'ectinlbranchlate Oaiteropod. 



IV. Primarily neural flexure modified by subsequent changes. 1, Lamclli- 

 branchiute Mollusc ; Neural Uolliufoiita. 2, Drachiopod ; 3, I'olycoon. 



V. Ilirmal Uollutcoidn (AKidlani). 1, simple hmmal flexure, as in Appcti- 

 dinilaria ; 2, after hiviiial flexure the Intestine is bent back, and an atrium 

 Is formed ; the branchial sac remains compara'ively small ; 3, the branchial 

 sac comparatively large. 



a, oral aperture ; 6, anal aperture, or extremity of the intcntine ; r, renal 

 organ ; pp, propodium ; mi, mesopodium ; ml, mctupodium ; if, ci>ipo<l>um; 

 t, branchial ; , auricle ; r, ventricle ; z, cerebral ganglia ; y, pedal ganglia; 

 II, hnmal region ; ff, neural region. 



[The letters hare the same signification In these and all the other figures, 

 with the exception of figure 10.] 



