O T T E R OWL. 



367 



formed plants, some species being shrubs, others 

 undcrshrubs, or herbaceous, with or without tuberous 

 roots. They are natives of South Africa, and belong 

 to Composites, are kept as green-house plants, and are 

 easy of management, and propagated by cuttings. 



OTTER. See LUTRA. 



OURAPTERYX (Leach). A genus of lepido- 

 pterous insects, belonging to the family of nocturnal 

 inoths (Geometridce), and distinguished by having the 

 hinder wings furnished with a pair of short tails. The 

 type is the swallow-tail moth (O. sambucaiia), a hanYl- 

 some moth of a pale brimstone colour, about an inch 

 and a half in expanse. It is not uncommon in the 

 neighbourhood of London. 



OUTEA (Aublet). A genus of shrubs and trees, 

 natives of both Indies, otherwise called Joutay. They 

 belong to Legumlnosce. 



O VIS, a most important genus of ruminating mam- 

 malia, of which an account will be given in the article 

 SHEEP. 



OVULA (Lamarck; BuLLA,Linnams). Bruguiere, 

 in the first instance, separated the shells of this genus 

 from those of the genus Bulla of Linnaeus, with which 

 they were confounded. Lamarck has properly adopted 

 the same association of species, but has divided them 

 into two families ; the first consisting of those which 

 have the right side of the aperture wrinkled or 

 thickened ; and the second of such as are smooth 

 on the right side ; in which he includes the species 

 having the last whorl attenuated, and producing long 

 beaks or rostra at both ends of the shell, as in the 

 Ovula volva, commonly called the weaver's shuttle. 

 The genus Ovula, as it is now constituted, forms a 

 very natural and well-defined association of species. 

 Its rank in a system of malacology is immediately 

 preceding the genus Cyprcea, to which it may be con- 

 sidered nearly allied, as the animal differs in no 

 essential characteristic. From the Cowry it may, 

 however, be readily distinguished, no spire being 

 formed, and both ends of the shell being continued in 

 uniformity with each, or nearly so, in most species ; 

 and another striking distinction is, that the columella 

 (lip) is never plaited, or, as it is sometimes called, 

 toothed. To the genus Sulla they also approximate, 

 being, like them, convolute shells ; but the rig-ht lip, 

 which is constantly folded, or reflected inwardly in 

 adult shells, and either smooth or wrinkled, is a 

 character quite opposite to that of the Sulla, in 

 which the lip is straight. The form of the Ovula 

 is ventricose like the Cyprcea, oblong, oval, or some- 

 times egg-shaped ; the whorls convolute, rolled upon 

 their own axis, the outer one very considerablv 

 larger, and inclosing all the others ; and in some 

 species both extremities are prolonged, and form 

 subcylindrical beaks, particularly in the O. volva, in 

 which we have seen examples where this attenuated 

 portion extended several inches from the central 

 point of the whorls. In other species, as the O. 

 gibbosa, the conformation of the whorls more nearly 

 resembles that of the Cyprcea, but they exhibit no 

 spire ; the edge of the right lip is always reflected 

 inwards, and either smooth, or somewhat wrinkled ; 

 there are no columella plaits ; the aperture is longi- 

 tudinal, narrow, and extending the entire length of 

 the shell ; it is also effuse, without any operculum or 

 epidermis. The mantle of the animal envelopes the 

 shell completely, folding over by a continuation on 

 one side ; while in the Cowry it is expanded on both 

 sides, and sometimes does not meet beyond a certain 



point, which may be traced in" some cases. In a 

 young state the lip is sharp, but at an adult age 

 it turns inwardly. This genus is the first of the six 

 genera into which Lamarck has divided the shells, 

 being spirally evolved on their own axis, viz. Ovula, 

 Cyprcea, Terebcllum, Ancillaria, Oliva, and Conus. 

 The two first only have their lip reflected inwards. 

 This genus is beautifully figured in a Monograph 

 published by Mr. Gray, F.R.S., to which we refer 

 our readers. These molluscs mostly inhabit the 

 Indian seas and those of the torrid zone. Some 

 species are known in a fossil state. The animal is 

 ably figured by Messrs. Quoy and Gaimard in the 

 Atlas of Plates to their Voyages. 



OWL (Stria:, or perhaps rather Strigidce, the owl 

 family), the common name of all the nocturnal birds 

 of prey. These birds are found in every country ; 

 and, though all of them are nocturnal, or rather cre- 

 puscular in their feeding, yet they are among the most 

 laborious of birds ; and the quantity of food which they 

 consume in proportion to the weight of their bodies, 

 is probably greater than that consumed by any other 

 birds. As is the case with the diurnal birds of prey, 

 taking them in the order of their disposition to prey 

 upon the living bodies of warm-blooded animals, 

 so, in the owls, the head-quarters may be said to be 

 in northerly and cold climates. In tropical countries, 

 indeed, there are plenty of owls, but they are not 

 birds of so bold a character as the owls of the north, 

 just as the vultures of the same countries are not so 

 bold birds as the northern eagles. 



There is a very singular adaptation of twilight and 

 twilight bird in this geographical distribution of the 

 owls, and, if properly followed out, it is one which is 

 calculated to throw no small light upon the mode in 

 which all the parts of nature are fitted to each other. 

 In the tropical country the twilight is very short, 

 nearly of the same length all the year round, and 

 under the equator itself there is only about an hour 

 and twelve minutes between sunset and absolute 

 night. In the polar regions again, and even in 

 temperate latitudes, the twilight is much longer. 

 At the poles there is light all night for a part of 

 the year, and bright twilight for a still greater part. 

 Upon a Shetland hill one can read the smallest print 

 with ease at midnight in summer, with fully more 

 ease indeed than it can be read at mid-day in winter 

 if the sky happens to be cloudy. Over all the northern 

 parts of the island of Great Britain, it is pleasant 

 walking light the whole night long ; and Nature's 

 night is so short, that hardly have the bitterns and 

 other evening birds ceased to deliver their notes, when 

 the birds of the morning are astir, and pouring forth 

 their morning songs. There is a great difference 

 between those morning songs and the evening notes 

 of the birds; all the latter are harsh and jarring, and 

 there is a monotony in the jar that tends to lull one 

 asleep, in the same manner as is done by the trick- 

 ling drops in a dripping cave, or the ticking of a clock. 

 The morning song again, whatever be its pitch, is 

 lively and inspiriting, and tends to shake off that sleep 

 which the evening song produces. It may be the 

 cackle of the grouse, the whistle of the plover, the 

 wail of the lapwing, or the glorious note of the lark 

 showered down from the top of the sky, as if to call 

 men to their labours ; but, be it what it may, it 

 comes thrilling over the mind like the spirit of the 

 morning, and inspires freshness into such as happen to 

 be abroad. 



