433 



POMACANTHUS. 



POPULUS. 



434 



PrtdericeUa, Gervais ; Van Beneden ; Thompson ; Allmnu ; 

 Johnston ; Hancock. 



Family 3. Paludicellidce. 



Lophophore orbicular, mouth destitute of valve. (Does uot perhaps 

 properly belong to the P. h : ppocrepia.) 



Gen. 1. Paludicella, Gervais. 



Polyzoary membrano corneous, branched ; branches composed of a 

 series of claviform cells, placed end to end, and separated from one 

 another by complete septa ; orifices tubular, lateral, placed near the 

 wider extremity of each cefl; ova lenticular, with a narrow annul us. 

 A Icyonella (sp.), Ehrenberg ; Nordmann. 



Paludicella, Gervais ; Van Beneden; Allmau; Thompson ; John- 

 ston; Hancock. 



POMACANTHUS. [CHJSTODOX.] 



POMA'CE^E. [ROSACE*.] 



POMATOMUS. [PERCID.E.] 



POME, a form of Fruit. [FRUIT.] 



POMEGRANATE. [PumcA.] 



POMPILIDE, a family of Fossorial Hymenopterous Insects. They 

 are sometimes included with the Sphegida:. [HYMENOPTERA.] They 

 have the collar either transversely or longitudinally square, with the 

 abdomen more or less oval, and attached to the thorax by a very short 

 peduncle. The legs are very long. The fore wings have two or three 

 perfect submarguial cells, and another commenced at the tip of the 

 wings. The species are called Sand Wasps, and are amongst the moat 

 ferocious of the insect tribes. The species of the exotic genus Pepsit 

 are amongst the largest of the ffymenoptera. The genus Pompilus is 

 British. The i-pecies are very active, running amongst grass and 

 other plants in hot sandy situations. They are quick in their motions, 

 and their wings are constantly agitated. Their long legs give them 

 the appearance of spiders. (Westwood, Families of Insect!,) 



POMPILIUS. [NAUTIUDA] 



PO'MPILUS, according to Latreille, a genua of Hymenopterous 

 Insects of the section Fonoret and family Sphegidce. lu the systems 

 of Dr. Leach, Mr. Shuckard, and some others, this group of insects is 

 regarded aa a family, Pompilidce, the principal characters of which are 

 as follows : Posterior legs at least as long as the head and thorax 

 taken together; antenna of the female formed of long joints, generally 

 distinct and often curved ; prothorax at least as broad again as long; 

 its posterior margin arched ; abdomen obovoid, without any long 

 petiole at the base. 



The Pompilidce are extremely active : they run and fly with great 

 rapidity ; are for the moat part of moderate size, and often adorned 

 with red and black colours; at least those species which belong to the 

 genus Pompilia. These insects burrow in the ground, preferring sandy 

 situations, and store their cells with spiders, which constitute the food 

 of their larvee. 



In the genus Pompilus the superior wings have one marginal cell, 

 which is semicircular, and sometimes nearly triangular; and three 

 submarginal cells ; the first of these is as long or longer than the two 

 following cells ; the second receives the first recurrent nervure about 

 its centre ; and the third, which ia either triangular or aubquadrate, 

 receives the second recurrent nervure. A fourth submarginal cell is 

 Bometimes traceable. 



This genua contains numerous species. Mr. Shuckard, in his work 

 on the indigenous Foaaorial Hymenoptera, describes 18 species. 



Besides Pompilus proper, the genera Ceropalea and Aporus are 

 included in the present family. 



PONERA (Latreille), a genus of Insects belonging to the family 

 Formicidce. In this genus the neuters and females are armed with a 

 sting. The peduncle of the abdomen is formed of a single knot ; 

 antennae in these individuals thickened at the tip; mandibles trian- 

 gular ; head subtriangular. P. conlracta is a small species, a native 

 of England. 



PONGO. [CHIMPANZEE.] 



PONTEDERA'CE^E, Pvntederadt, a natural order of Plants belong- 

 ing to the class of Endogens. It has a 6-parted tubular coloured 

 perianth, more or less irregular, with a circinate testivation. The 

 stamens arising from the calyx 6 or 3 opposite the petals, the anthers 

 turned inwards, opening lengthwise. The ovary is free, more or less 

 completely. 3-celled, many-seeded ; one style, the stigma simple. The 

 capsule 3-celled, occasionally acquiring an adhesion to the perianth, 

 3-valved with loculicidal dehiscence; the seeds are indefinite, attached 

 to a central axis ; ascending hilum small ; the embryo with its radicle 

 rather enlarged, orthotropal in the axis of somewhat mealy albumen. 

 The species are aquatic or marsh plants. The leaves sheathing at the 

 base, with parallel veins in the larger species, arrow-headed, cordate, 

 or dilated. The flowers are either solitary or in spikes or umbels, 

 apathaceous ; frequently blue, sometimes yellow. The aquatic plants 

 comprehended in this order are distinguished by the divisions of their 

 flowers being rolled inwards after flowering, to which may be added 

 mealy albumen and an indefinite number of seeds. They are nativea 

 exclusively of North and South America, the East Indies, and tropical 

 Africa. Very little in known of their uses. Some of the species are 

 employed by the native Indian practitioners in liver complaints and 

 diseatea of the stomach. 



Rubbed down in butter and drank, thiiy are said to remove redness 

 HAT. niOT. DIV. vol.. iv. 



of the eyea ; powdered and mixed with sugar, to relieve asthma ; 

 and when chewed, to remove tooth-ache ; brayed with milk, some are 

 administered in fever and some eaten as pot-herbs. 



(Lindley, Vegetable Kingdom.) 



PONTO'PHILUS, a genus of Shrimps. (Egeon. Risso.) 



PONTOPORIA. [CETACEA.] 



POONAHLITE, a Mineral occurring crystallised in long slender 

 crystals. Primary form a right rhombic prism. Fracture uneven. 

 Colourless. Hardness 5'0 to 5'5. Transparent, translucent. Lustre 

 vitreous. Found at Poonah in the East Indies. 



The following is an analysis by Gmeliu : 



Silica 45-120 



Alumina :;i;-| Hi 



Lime 10-197 



Soda, with a trace of potash . . . 00-657 

 Water 13-386 



POPINJAY. [PICIDJS.] .99-806 



POPLAR. [POPULUS.] 



POPPY. [PAPAVER.] 



POPULUS (from the Latin Populus), a genua of Plants belonging 

 to the natural order Salicaceai. It is characterised by possessing 

 dioecious cylindrical many-flowered catkins; wedge-shaped single- 

 flowered jagged bractese or scales ; turbinate calyx, tubular below, 

 and dilated in the border. The barren flowers have eight or more 

 capillary very short filaments, and large drooping quadrangular 

 anthers. The fertile flowers have an ovate pointed ovary, no style, 

 4-8 awl-shaped atigmas; ovate capsule, with two concave valvea and 

 one cell ; numerous small ovate seeds, each crowned with a tuft of 

 fine hairs. All the apecies of this genus are deciduous trees, mostly 

 of a large size, and growing in Europe, North America, Asia, and the 

 north of Africa. The Poplar has long been valued as an ornamental 

 tree, and the various species have been extensively cultivated in 

 Europe. As they are diceeioua plants, much difficulty has arisen in 

 determining the number of the introduced species ; and it is probable 

 that when the plants with male and female flowers shall have been 

 carefully examined, a considerable reduction in the present number of 

 acknowledged apecies will take place. 



P. alba, the White Poplar, or Abele Tree, has rouudish, cordate, 

 lobed, and toothed leaves, glabrous above, downy and very white 

 beneath ; fertile catkins, ovate ; 4 stigmas ; creeping roots ; branches 

 very white, downy when young. This tree is a native of Great 

 Britain and most parts of Europe, in woods and thickets in a moist 

 soil. 



P. canesceiis, the Gray Poplar, is by some writers considered only 

 a variety of P. alba. It is known by its leaves being roundish, deeply 

 waved, toothed, downy, and hoary beneath ; fertile catkins cylindrical ; 

 stigmas 8. This tree is of slower growth than /'. alba, and the wood 

 is finer, and more adapted for the purposes to which timber is applied. 

 The Abele, as well as the Black Poplar, was known to the Romans, 

 and was recommended by Pliny aa props for the vine. (' Hist. Nat.,' 

 xvi. 23.) It is much planted in some parts of Holland, Flanders, 

 France, and Germany. The principal use to which the Abele is put 

 in England is that of making flooring boards, for which purpose it 

 should be seaaoned eighteen or twenty months previous to use. It is 

 also employed by the cooper for making wooden dishes, casks, &c. 

 The Gray Poplar possesses the whitest wood of any of the species, 

 and is used in France and Germany for carving and the lighter kinds 

 of architecture. 



P. tremula, the Trembling Poplar, or Aspen. Leaves nearly orbicular, 

 broadly toothed, glabrous on both sides ; atalks compressed ; stigmas 

 4, erect, cased at the baae. Ten or twelve varieties of this plant are 

 found in the nurseries, and some writers refer several other species to 

 this aa varieties. The aspen, like all the genus, is a rapid-growing 

 tree. It has horizontal branches, which become pendulous by age. 

 It is a native of moist woods in Great Britain, and in Scotland is 

 found at an elevation of 1500 feet above the level of the sea. It is 

 also found in the whole of the south of Europe, in the Caucasus, in 

 Lapland, and is very abundant in Russia. The wood of this tree Is 

 used for much the same purposes as the last. 



The trembling leaves of the Aspen have always excited attention, 

 and have frequently been the subject of superstitious belief and 

 poetical allusion. 



P. trepida, the American Aspen, is by some looked upon as a 

 variety of P. tremula. The leaf ia auborbiculate, with an abruptly 

 acuminate point, toothed, with two glands at the base on its upper 

 surface; silky whilst young, glabrous afterwards. It ia found in North 

 America. 



P. nigra, the Black Poplar. Leaves twice the length of their foot- 

 stalks, deltoid or unequally quadrangular, serrated with glandular 

 teeth, glabrous ; the base more entire, the under side palest ; catkins 

 cylindrical, pale, lax. It is a native of Great Britain, and has a 

 geographical range nearly the same aa that of /'. alba. It attains a 

 height of from 70 to 80 feet, and, on account of its rapid growth, has 

 been much cultivated. The wood is used for the same purpose as 

 that of P. tremula; it is however softer, and more eoay to work, and 

 splita more eaaily than any other of the species. The cotton from 

 the eeeda has been used in France and Germany as wadding, and ha.* 

 been also manufactured into cloth-hats and paper; but the expense 



2 F 



