| Ordovician | Caradoc | Dicranograptus—shales. Defrel or Orthis | |
| Llandeilo Group | Rhyolitic ashes = Upper Massive ashes = Middle Acid andesitic ashes = Lower | Upper Ashes of Arenig. | |
| Daerfawr Shales. | Zone of Didymograptus Murchisoni. | ||
| Platy ashes Great Agglomerate | Lower Ashes of Arenig (Hypersthene Andesites). | ||
| Arenig Group | Olchfa or Bifidus—shales | (Didymograptus bifidus). | |
| Filltirgerig or Hirundo Beds Erewnt or Ogygia—limestone | Didymograptus Hirundo. | ||
| Henllan or Calymene—ashes Llyfnant or Extensus flags Basal Grit | Didymograptus extensus. | ||
 | |||
| (unconformity) | |||
The above succession is divisible into: (1) a lower series of gritty and calcareous sediments, the “Arenig Series,” as it is now understood; (2) a middle series, mainly volcanic, with shales, the “Llandeilo Series”; and (3) the shales and limestones of the Bala or Caradoc Stage. It was to the middle series (2) that Sedgwick first applied the term “Arenig.”
In the typical region and in North Wales generally the Arenig series appears to be unconformable upon the Cambrian rocks; this is not the case in South Wales. The Arenig series is represented in North Wales by the Garth grit and Ty-Obry beds, by the Shelve series of the Corndon district, the Skiddaw slates of the Lake District, the Ballantrae group of Ayrshire, and by the Ribband series of slates and shales in Wicklow and Wexford. It may be mentioned here that the “Llanvirn” Series of H. Hicks was equivalent to the bifidus-shales and the Lower Llandeilo Series.
References.—Adam Sedgwick, Synopsis of the Classification of the British Palaeozoic Rocks (1885); Sir A. Ramsay, “North Wales,” Geol. Survey Memoir, vol. iii.; C. Lapworth, Ann. Mag. Nat, Hist. vol. vi., 1880; G.A.J. Cole and C.V. Jennings, Q.J.G.S. vol. xlv., 1889; C.V. Jennings and G.J. Williams, ibid. vol. xlvii., 1891; Messrs Crosfield and Skeat, ibid. vol. lii., 1896; G.L. Elles, Geol. Mag., 1904; J.E. Marr and T. Roberts, Q.J.G.S., 1885; H. Hicks, ibid. vol. xxxi., 1875. See also [Ordovician].
(J. A. H.)
AREOI, or Areoiti, a secret society which originated in Tahiti and later extended its influence to other South Pacific islands. To its ranks both sexes were admitted. The society was primarily of a religious character. Members styled themselves descendants of Oro-Tetifa, the Polynesian god, and were divided into seven or more grades, each having its characteristic tattooing. Chiefs were at once qualified for the highest grade, but ordinary members attained promotion only through initiatory rites. The Areois enjoyed great privileges, and were considered as depositaries of knowledge and as mediators between God and man. They were feared, too, as ministers of the taboo and were entitled to pronounce a kind of excommunication for offences against its rules. The chief religious purpose of the society was the worship of the generative powers of nature, and the ritual and ceremonies of initiation were grossly licentious. But the Areois were also a social force. They aimed at communism in all things. The women members were common property; the period of cohabitation was limited to three days, and the female Areois were bound by oath at initiation to strangle at birth any child born to them. If, however, the infant was allowed to survive half an hour only, it was spared; but to have the right of keeping it the mother must find a male Areoi willing to adopt it. The Areois travelled about, devoting their whole time to feasting, dancing (the chief dance of the women being the grossly indecent Timorodee mentioned by Captain Cook), and debauchery, varied by elaborate realistic stage presentments of the lives and loves of gods and legendary heroes.
AREOPAGUS (Ἄρειος Πάγος), a bare, rocky hill, 370 ft. high, immediately west of the northern rim of the acropolis of Athens. The ancients interpreted the name as “Hill of Ares.” Though accepted by some modern scholars, this derivation of the word is rendered improbable by the fact that Ares was not worshipped on the Areopagus. A more reasonable explanation connects the name with Arae, “Curses,” commonly known as Semnae, “Awful Goddesses,” whose shrine was a cave at the foot of the hill, of which they were the guardian deities (Aeschyl. Eumen. 417, 804; Schol. on Lucian, vol. iii. p. 68, ed. Jacobitz; Paus. i. 28. 6).
The Boulē, or Council, of the Areopagus (ἡ ἐν Ἀρείῳ Πἀγῳ βουλή), named after the hill, is to be compared in origin and fundamental character with the council of chiefs or elders which we find among the earliest Germans, Celts, Romans, and other primitive peoples. Under the kings of Athens it must have closely resembled the Boule of elders described by Homer; and there can be no doubt that it was the chief factor in the work of transforming the kingship into an aristocracy, in which it was to be supreme. It was composed of ex-archons. Aristotle attributes to it for the period of aristocracy the appointment to all offices (Ath. Pol. viii. 2), the chief work of administration, and the right to fine or otherwise punish in cases, not only of violation of laws, but also of immorality (ibid. iii. 6; cf. Isoc. vii. 46; Androtion and Philochorus, in Müller, Frag. Hist. Graec. i. 387. 17, 394 60).[1] This evidence is corroborated by the remnants of political power left to it in later time, after its importance had been greatly curtailed, and by the designation Boule, which in itself indicates that the body so termed was once a state council. In a passage bearing incidentally upon the early constitution of Athens, Thucydides (i. 126. 8) informs us that at the time of the Cylonian insurrection the Athenians, we may suppose in their assembly (Ἐκκλησία), commissioned the archons with absolute power to deal with the trouble at their discretion. From this passage, if we accept the Aristotelian view as to the early supremacy of the Areopagitic council, we must infer that a modification of the aristocracy in a popular direction had at that time already taken place.