149 



OXYBELUS. 



PACHYDERMATA. 



150 



0. ttricta has an erect leafy stem, umbelliferous peduncles rather 

 shorter than the leaves. It is a native of North America, and is 

 naturalised in Cornwall and Devonshire in England. Tha flowers are 

 yellow and about the siza of those of 0. corniculata. Browne says, 

 this plant is also a native of Jamaica, and he recommends it as a 

 pleasant cooler and diuretic; formerly it was given in inflammatory 

 cases, but has been superseded by the more agreeable fruit-acids which 

 are now cultivated ia the West Indies. Professor Morren of Liege 

 attributes to this species of O.calis the peculiar properties of a sensitive 

 plant. He also observed the same movements in 0. Acetosella and 0. 

 comicnlata, and some other species. The 0. senaitira, called by De 

 I 'andolle Biophytum on account of its sensitive properties, has long 

 been known to possess this quality. The whole genus of Ojcalis is 

 curious and beautiful, and well worthy cultivation. There are above 

 220 species described, which are distributed in every quarter of the 

 globe. 



(Don, DiMamydeous Plants; Babington, Manual of British Botany; 

 Lindley, Flora Medico.) 



OXYBELUS. [NYSSOSID.B.] 



OXYC'OCCUS, a genus of Plants belonging to the natural order 

 Ericacete. 



0. paluttrit, the English Cranberry, is found wild abundantly in the 

 fens of Norfolk, Lincolnshire, and many other parts of England, 

 always by the side of little rills, and not among stagnant water ; it has 

 slender trailing thread-like shrubby shoots, clothed with tiny linear 

 leaven, and has a 5-parted pink corolla with the segments sharp- 

 pointed and turned back. The fruit is a round austere red berry, 

 which makes excellent tarts and one of the many kinds of marmalade. 

 The Russian cranberries of the shops are borne by this specks. They 

 are not gathered till after the disappearance of winter. Near St. Peters- 

 burg the cranberry plant is so common, that the snow is stained 

 crimson by the berries crushed to pieces by the passage of sledges 

 over them. 



O. macrocarpiu, the American Cranberry, is very like the other, but 

 it? leaves, flowers, and fruit, are larger ; and the latter has a more 

 medicinal taste. It is imported from the United States, in hogsheads, 

 in considerable quantity, and used for the same purposes as the other; 

 but it is considered of inferior quality. [V.VCCINIPM.] 



OXYLOPHUS. [Cncouna.1 



OXYNASPIS. [ClRRIPEDIA.] 



OXYNOTUS. [LAXIADJB.] 



OXYRHYN'CHS, a name given by M. Latreille to a great division 

 of Brachyurous CVtwdicea, consisting of the Naiadir, the Oxystome, 

 and many of the Anomura (Anomoures^of M. Milne-Edwards. The 

 latter zoologist however remarks that as the classification in which 

 the term was employed has been long abandoned even by its author, 

 he (M. Milne-Kdwards) had thought that it would not be inconvenient 

 to apply it to another family, and so avoid the necessity of adding a 

 new name to zoological nomenclature. 



The natural group to which M. Milne-Edwards applies the name 

 ' Oxyrhinque,' is that which presents a nervous system more centralised 

 than he has as yet discovered among the Crustaceans, and it is prin- 

 cipally for that reason that he places the Oxyrhynchs at the head of 

 the series formed by these animal". In fact, he observes, the different 

 medullary ganglions of the thorax do not, in this instance, form more 

 than a single solid mass in the form of a disc, whilst in the other 

 Decapods, of which the internal anatomy is known, these same 

 ganglions remain more or less distinct, and only unite so as to form a 

 circular ring. In many of the Oxyrhyncbs M. Milne-Edwards has 

 also remarked that the two portions of the liver, instead of being 

 completely separated as in the other Decapods, are united on the 

 median line by an unequal lobe : this viscus is well developed and 

 extends over a great part of the vault of the branchial cavity. The 

 number of bniuchise is always nine on each side of the thorax ; seven 

 of these organs, the last of which is inserted above the third foot, are 

 very much developed, and rest on the vault of the sides, whilst the 

 two others are often reduced to the rudimentary state, and are hidden 

 at the base of the first. Lastly, the vault of the respiratory cavity 

 is but slightly elevated, and throughout its extent, nearly comes in 

 contact with the upper surface of the b ranch i;e. The rest of the 

 internal organisation offers nothing peculiar. 



But the same assertion cannot be made with regard to the external 



organisation of these animals. The general form of their body 

 approximates to that of a triangle, of which the base is rounded and 

 turned backwards. The first pair of feet are generally of the same 

 size on each side ; but their dimensions are very different in some 

 species and also in the sexes. The succeeding feet are often of 

 enormous length, and are nearly always slender and cylindrical ; this 

 disposition is even carried so far in some of the Oxyrhynchs that it 

 has obtained for them the name of Sea-Spiders. The second or third 

 last pairs are sometimes subcheliforrn ; but these organs never take 

 the form of natatory fins, and in general those of the last three pairs 

 diminish gradually in length. 



The Oxyrhynchs are all essentially marine. None are known to 

 live in fresh-water or to frequent the shores of the sea ; but all inhabit 

 great depths, and are generally obtained when dredging for large fish. 

 Their long feet would convey an idea of nimbleness, but these Crustacea 

 are in general slow in their motions, and soon die out of water. No 

 swimmers are known among them. 



OXYRHYNCHUS. fPicic.E.] 



OXY'RIA, a genus of Plants belonging to the natural order Polygo- 

 nacece (!). It has a 4-parted perianth, the 2 interior segments larger; 

 6 stamens ; 2 stigmas ; a 1-seeded nut, compressed, with a membranous 

 wing, larger than the persistent segments of the perianth ; embryo 

 central. 



0. reniformii, Mountain-Sorrel, is the only species. It is found on 

 the highest mountains of Great Britain, and is an inhabitant of Europe. 

 It is the 0. digyiria of many botanists. 



(Babington, Manual of British Jiotany; Koch, Flora (rennanica). 

 OXYSTOMA, or OXYSTOMES, a name applied by M. Milne- 

 Edwards to the fourth and last family of Brachyurous Crustacea 

 (type, Leucosia, Fabr.), comprising all the Crustacea which most 

 resemble the type in their general organisation, and especially in the 

 conformation of the buccal apparatus. 



The apertures for the passage of the intromissive organs of the 

 males are hollowed out in the basilary joint of the posterior feet, as 

 in the Oxyrhynchs and the Cyclometopes. The disposition of the 

 branchia* is also nearly the same as in the last-named group, but 

 sometimes the number of these organs is less considerable, and does 

 not amount to more than six on each side. In most of these crusta- 

 ceans the branchial cavity does not present at the base of the feet 

 any aperture for the entrance -of the water necessary for respiration, 

 and this liquid only arrives there by a gutter hollowed out on each 

 side of the prelabial space, serving as a passage for the water expelled 

 from the branchial cavity. This canal is very long in nearly nil tho 

 Oxystomes, and is converted into a species of tube by a prolongation 

 of the anterior jaw feet. The internal soft parts have not as yet been 

 discovered to present any particular organisation. M. Milne-Edwards 

 divides the family into the following tribes tho Leucosinns, the 

 Calappians, the Corystians, and the Dorippians. 



The Leucosians embrace the following genera: Arcania, Philyra, 

 Myra, Ilia, Ouaia, Leucoiia, Pertephona, Nuriia, Eualia, Oreophorut, 

 Iphit, and fjxt. 



The Calappians embrace the genera Calappa [CAT.AI'PA], Platymera, 

 ifwria, Orythia, Matuta, and Jfepattu. [HKPATUS.] 



The Corystians include the following genera: Atelycifclus, Thin, 

 Polydectus, Coryttet [CoRYSTgs], A'awtilocryttet, and Paeudocoryatea. 



The Dorippians include the following genera : Dorippe [DORUTA], 

 Cymopolia, Caphyra, and Ethusa. [ETIU'SA.] 



OXY'STOMUS. [STURXID.E.] 



OXYURA. [DUCKS.] 



OXYU'RUS (Swainson), a genus of Birds. 



OYSTER. [OSTKACEA; PmatOSDM.] 



OYSTER-CATCHER. [CHABADBIAD.E.] 



OYSTER-QUEEN. [Ur.vA.] 



OZOKERITE, a Mineral, consisting of Carburet of Hydrogen. 

 Colour yellowish-brown ; translucent ; has a slight bituminous odour, 

 and softens by the heat of the hand, so that it may be kneaded. Fuses 

 readily, emitting a stronger bituminous odour; burns with a clear 

 bright flame without residue. Insoluble in water, only slightly in 

 alcohol, but readily in ether and oil of turpentine. It is found in 

 considerable masses at Slanik in the Buchau district of Moldavia, and 

 is used for fuel. It contains Carbon, 85'204 ; Hydrogen, 13787. It 

 appears to be similar in composition to Hatohetine. 



PACA. 



r PAUIYCKI'HALA. . 



PAOHYCKPHAU'N.K, Swainson's name for the 'Great-Headed 

 Chatterers, which form, according to his first arrangement, the second 

 nub-family of the Ampelidie, or family of Chatterer*, and are placed 

 IwtWKcn Leiotric/iana (Long-Legged Chatterers) and BombyciUina 

 (Swallow Chatterers), the other two sub-families being the Ampelina, 

 ie Chatterer*, and the Pifirinrt, or Mnnakin Chatterers. <)f these 



sub-families he considers LeiotrickaiUf, Pachyceph'tlinrf, and Bombycil- 

 linte to be aberrant. 



1'ACHYCO'RMUS (Agassiz), agenus of Ganoid Fosil Fishes. [Fisn.] 

 PACHYDE'RMATA (literally Thick Hides; Dickliiiuter of the 

 Germans; Pachydermes of the French), the seventh order of Mam- 

 malia according to the system of Cuvicr. 



The first family of Pachyderms in thin arrangement consists of those 

 which have a proboscis and tusks, and which are ii'imo'1 Proboscideans. 



