PAL 



[ 194 ] 



PAP 



illse are termed the palpi maxillares, or 

 maxillary feelers; those placed laterally 

 upon the labium, are designated the palpi 

 labiales, or labial feelers. 

 PALUDI'NA. A genus o f fresh- water uni- 

 valves, belonging to the family Peristo- 

 mata. Several species, Paludina elon- 

 gata, Paludina fluviorum, Paludina cari- 

 nifera, &c. have been found in the Weal- 

 den formation. 



PA'NCAKE. The name given by Klein to 

 the Echinodiscus laganum, a species of 

 fossil echinus, belonging to the division 

 Catocysti. 



PANDA'NEA. } (from pandus t Lat. crooked.) 



PANDA'NUS. $ The screw-pine, so named 

 from the spiral arrangement of its leaves, 

 is a monocotyledonous tree, growing 

 only in the warmer zones, and princi- 

 pally near the sea. The pandanea, like 

 the cocoa-nut palm, is generally the first 

 vegetable colonist of the newly-raised 

 coral islands. Its appearance is that of a 

 gigantic pine-apple plant with arbores- 

 cent stems. The pandanus bears a large, 

 spherical, drupaceous fruit : the seed 

 within each drupe being enclosed within 

 a hard nut. From the pandanus growing 

 near to the sea, its fruit frequently drops 

 into the water, and is drifted by the 

 waves and winds to distant shores : thus 

 the elements of vegetation are transported 

 to the emerging coral islands, where it 

 vegetates. A fossil* fruit of the pan- 

 danus was found by Mr. Page in the in- 

 ferior oolite, and is in the Oxford mu- 

 seum. It is of the size of a large orange, 

 and is covered by a stellated rind, or epi- 

 carpium, composed of hexagonal tuber- 

 cles, forming the summits of cells which 

 occupy the entire surface of the fruit. 

 Fruits of a genus, to which M. Adam 

 Brongniart has given the name of Pan- 

 danocarpum, occur, together with cocoa- 

 nut fruit, at an early period of the ter- 

 tiary formations, in the London clay of 

 the Isle of Sheppey. 



PA'NGOLIN. A species of manis, or scaly 

 lizard ; called also the scaly ant-eater. Its 

 armature is composed of separate, horny, 

 moveable scales. It is destitute of teeth, 

 has a very extensile tongue, and lives on 

 ants and termites. 



PA'NICLE. (panicula, Lat. a bunch or 

 cluster.) A species of inflorescence, in 

 which the flowers are scattered on pedun- 

 cles, variously subdivided without any 

 order, and more or less close. The oat 

 affords a familar example. When the 

 middle branches of a panicle are longer 

 than the others, it is termed a thyrsus. 



PANNI'CULUS CARNO'SUS. (from panni- 

 culus, a cloth, and carnosus, fleshy, Lat.) 

 A peculiar set of sub-cutaneous mus- 

 cular bands which serve to erect the bris- 



tles, or armour, of certain animals ; as 

 the hedge-hog, porcupine, &c. 



PANOP^E'A. A genus of bivalve shells of 

 the faaiily Solenacea. The panopsea is a 

 transverse inequilateral bivalve, gaping 

 at both extremities. The hinge similar 

 in both valves, with an acute cardinal 

 tooth in each, and, on the right valve, a 

 little pit, which receives the tooth of the 

 opposite valve. 



This shell appears to be of a mixed 

 genus between mya and solen. It is 

 found both recent and fossil, but no great 

 deal appears to be known of the recent 

 species. 



PA'PER COAL. A bituminous shale, to 

 which the name has been given from its 

 divisibility into extremely thin leaves. In 

 the brown coal formation, and in the 

 surturbrand, are found beds that divide 

 into laminae, as thin as paper, and are 

 composed entirely of a congeries of many 

 kinds of leaves. 



PA'PER NAU'TILUS. Called also the Paper 

 Sailor. See Argonauta. 



PAPI'LIO. (papilio, Lat. a butterfly.) A 

 genus of the family Diurna, belonging to 

 the order Lepidoptera. The butterfly. 

 The species are numerous. It has been 

 weU observed that the chrysalis is the 

 tomb of the caterpillar, and the cradle of 

 the butterfly. 



PAPILIONA'CEOUS. Resembling a butterfly. 

 In botany, the corolla is called papiliona- 

 ceous when it consists of five petals of 

 particular forms, of which the uppermost 

 is generally the largest, and turned back ; 

 the two next resemble each other, but 

 differ from the first ; they have their 

 faces turned towards each other, and are 

 called the alee ; the two lowermost are 

 generally united by their lower edge, and 

 form a keel-like figure, and are, from that 

 circumstance, called the carina or keel ; 

 the two last, so united, contain, and pro- 

 tect, the internal organs. 



PAPI'LLA. (papilla, Lat.) This word is 

 generally used in the plural, papillae. 

 Malpighi first discovered this structure 

 in the foot of the pig, and gave to it its 

 name. The external surface of the skin 

 presents a great number of minute pro- 

 jecting filaments ; these are the papillae. 

 " It is probable," says Dr. Roget, "that 

 each of these papillae contains a separate 

 branch of the nerves of touch, so that 

 we may consider these papillae as the 

 principal and immediate organs of touch. 

 The papillae are much more easily per- 

 ceived on some parts than others, but no 

 where are they more perceptible than on 

 the tongue, where, more especially in a 

 morbid condition of the body, they are 

 frequently much elevated. 



PAPI'LLOUS. (from papilla, Lat. a pimple.) 



