PLIOCENE SYSTEM 



PLOMBIERES 



241 



not be sought out on suspicion, but that, if accused 

 and convicted of holding that faith, they should be 

 punished. Accusations unsupported by an accuser 

 were not to be received, while suspected cases were 

 to have an opportunity of clearing themselves by 

 offering prayers to the Roman gods (diis nostris). 



Kail's text of the Epistles and Panegyricus (Leip. 

 1853 ) is the best, while a useful selection with a good 

 commentary has been published by Church and Brodribb 

 ( 1871 ). Melmoth's translation ( 1746 { is free and emin- 

 ently readable; Orrery's, of the Epistles (1751), is still 

 esteemed. 



Pliocene System. Strata belonging to this 

 system are restricted in Britain to a limited area in 

 Essex, Suffolk, and Norfolk ; but a few isolated 

 patches occur also in Cornwall and Kent. They 

 consist of irregular lenticular beds of sands and 

 shelly gravels, &c., which never occur altogether in 

 one place. The whole series probably does not 

 exceed 120 feet in thickness, and comprises the 

 following groups arranged in descending order : 



CROMEB FOREST-BED : fresh-water or estuarine silts, clays, and 

 units, with layers of peat ; 10 to 70 feet thick. The fossils 

 are land and fresh-water molluscs, many land-plants, and 

 numerous mammalian remains. 



CHILLESFORD BEDS : sands and clays; 6. to 16 feet thick; con- 

 tain marine shells, some two-thirds of which are existing 

 Arctic species. 



NORWICH CRAO : nuvio-marine gravel, sand, and loam ; 5 to 10 

 feet thick. Fossils, chiefly marine molluscs; several land 

 and fresh-water shells ; anu numerous mammalian remains 

 hence the name of ' mammaliferous crag ' sometimes applied 

 to this group. Of the shells 93 per cent, are living species 

 14-ii per cent, being northern forms. 



RED CRAO : red ferruginous shelly sand, 25 feet thick, but local 

 and Inconstant. About 90 per cent, of the numerous shells 

 occurring in this deposit are existing species 10*7 per cent, 

 being northern forms. 



LKNHAU BEDS : Hands, Ac., occupying ' pipes ' or hollows in the 

 chalk of the North Downs, some 60X1 feet above the sea. 



8r ERTH BEDS : clays and gravels, near 8t Erth, Cornwall ; 

 many shells, about 40 per cent, being of extinct species. 



WHITE OB CORALLINE CRAO : shelly sands and clays ; fossils 

 abundant ; 84 per cent, of the shells are living species, and of 

 these 6 per cent, are northern forms. Polyzoa (popularly 

 called oorok)are numerous, hence the name sometimes applied 

 to this group. 



On the Continent Pliocene marine deposits are 

 met with in various countries, usually in maritime 

 regions, as at Antwerp and in the west of France in 

 the. Cotentin, Morbihan, and Aijuitaine. But it is 

 in the Mediterranean basin that this system attains 

 its greatest development. Thus, at various points 

 along the foot of the Alps in North Italy Pliocene 

 beds appear, and they likewise occur along both 

 sides of the Apennines, forming the sub-Apennine 

 formation ; while in Sicily they attain a thickness 

 of 2000 feet. In middle Europe the most important 

 Pliocene strata are the -fresh-water beds of the 

 Mayence basin, and the fresh and brackish water 

 beds of the Tertiary basin of Vienna. The calcare- 

 ous tufas of France and Italy belonging to this 

 system are notable for their plant-remains. 



Life of the Period. The flora of Pliocene times 

 indicates a more temperate climate than that of 

 the preceding Miocene. Many Miocene forms still 

 lived in Kuro|>e, but the palms and other character- 

 i^ii': Miocene plants hail disappeared. Ivy, plat- 

 anus, liqtiidambar, various maples, many walnut 

 trees, elms, hornbeams, magnolia, tulip-tree, Can- 

 ary laurel, oleander, vine, glyptostrobus, sassafras, 

 and others ranged from Tuscany to the heart of 

 France such plants as beech, poplar, lime, oak, 

 sassafras, maples, bamboos, vines, &c. growing 

 amongst the mountains of Cantal. The general 

 character of the flora recalls the Moras of distant 

 regions North America, the Canary Islands, 

 eastern Asia, and Japan. The abundant ever- 

 green plants of the period seem to have grown 

 eliiefly on the low grounds ; at higher elevations 

 pines and deciduous trees were the prevailing forms. 

 The flora of the Norwich Crag shows that towards 

 the close of the period the British area was clothed 

 380 



with a vegetation somewhat similar to that of the 

 present. The molluscan fauna includes an increas- 

 ing number of living species. In the lower groups 

 of the system the general facies of the shells is 

 southern, but in the upper groups the southern 

 types decrease in importance and are gradually 

 replaced by temperate and northern forms. 

 Amongst land animals we find several survivors 

 from earlier times, such as Dinotherium and Mas- 

 todon, with which co-existed many other pachy- 

 derms elephants, rhinoceroses, hippopotamuses, 

 and tapirs. Herbivorous quadrupeds also abounded 

 horses, giraffes, and various cervine and bovine 

 forms. Carnivores (panthers, bears, wolves, &c. ) 

 were well represented, and apes and monkeys also 

 formed a marked portion of the fauna. The Plio- 

 cene beds of Pikermi in Attica, and of India 

 (Siwalik group), have yielded a large number of 

 extinct and living types. At Pikermi occur the 

 remains of many ruminants, amongst which are 

 species of giraffe, Helladotherium, and various 

 cervine and bovine forms, together with Mastodon, 

 rhinoceros, Dinotherium, hysena, and others. The 

 Siwalik beds contain Hyasnarctos, Machairodus, 

 and other Miocene forms, and Sivatherium and 

 Bramatherium, gigantic four-horned animals allied 

 to antelopes. With these are associated many 

 living genera, such as Felis, Hyaena, Canis, Bos, 

 Bison, Capra, Ovis, &c. It niay be noted that 

 from the Pliocene of the Upper Missouri region 

 of North America remains of an abundant mam- 

 malian fauna have also teen obtained a fauna 

 which had a strikingly oriental aspect. 



In Pliocene times the Mediterranean covered 

 many tracts which are now dry land. The valley 

 of the Po then formed a great arm of the sea which 

 penetrated into the mountain-valleys of the Alps, 

 while Italy and Sicily were largely submerged. 

 Considerable tracts in the maritime districts of 

 southern and western France were likewise under 

 water. The sea also overflowed some part of the 

 south of England (Cornwall and Kent) and en- 

 croached upon the low grounds of Belgium and 

 East Anglia. The long arms of the sea, which in 

 the Miocene period had stretched from the Medi- 

 terranean through France into Switzerland and 

 the valley of the Rhine, had vanished, while fresh- 

 water and saline lakes occupied part of the area in 

 Austria-Hungary which hail been more or less open 

 sea in Miocene times. Much of south-eastern 

 Europe, however, continued submerged the sea 

 extending through the Aralo-Caspian depression 

 into Asia. One of the most notable events of the 

 Pliocene was the birth of Etna, Vesuvius, and the 

 now extinct volcanoes of Central Italy. In early 

 Pliocene times the climate was mild and genial, 

 but the conditions became less so during the clos- 

 ing stages of the period. This change is evidenced 

 particularly by the increasing number of northern 

 molluscs and 'the occurrence of ice-floated erratics 

 in the English Pliocene. 



Pliosaurus. See PLESIOSAURUS. 



IMock (Ger. Plozk), a town of Russian Poland, 

 on the right bank of the Vistula, 60 miles NW. of 

 Warsaw. Its principal building is the cathedral, 

 built in the llth century. One of the oldest towns 

 in Poland, Plock was the capital of ancient 

 Masovia, and was severely ravaged by the heathen 

 Prussians, the Lithuanians, and the Swedes. Pop. 

 ( 1895) 20,660, including many Jews. 



Plojeshtl, or PLOESCI, a town of Roumania, 

 .37 miles by rail N. of Bucharest, with petroleum- 

 refineries and a large trade in wool. Pop. 33,691. 



IMoillbieres, a spa in the French department 

 of Vosges, 14 miles S. of Epinal, sprang into 

 fashion through the favour of Napoleon ITT., 

 though the virtues of its waters were known e v tr 



