HOLARCTIC REGION( from nk. vos. ]roles, entire cipicriK6s, arktikos, northern. from dpk• T 0 T. (1 (1R, bear). A division in zo;;geography, defined in two senses: Ill the larger sense the term is used. unh appily. as at synonym for 'Aretliglea.' (St `e 111 1111 1111N ur _\ xotAl.s and NoTtn..1.A.) This 'region' embraces all of the Northern Hemisphere except the hot coast regions of Central Ameriea, all of Africa and kladagascar. and an indefinite extent of the and Polynesian islands, where its boun daries Aa•y in dit•erent elasses of animals; ill other words, it is a combination of the Nearc tic. Palwaretic, Palwotropieal. and Oriental re gion. of Selater and 11 allaee. as opposed to the combined Neotropieal and A ust ra la sia regions Notog.ca I. Thr fundamental 1 i between Ai clogali 11 1111 NI /1 11:181: to an early geological period, while many of the present dis tinctions between their subdivisions disappear when trneed back to the when the dis tribution of animal life was '1 (1 i f11)111 1111W. 1 1. is this 18'8811 i(•1V, than the naidern aspect, which has led naturalists to the generalizations of Aretog:ca and Notoga•a. Limiting the comparison to Nert•hrate animals, the eliarneteri,t of Aretoga•a are in outline as follows: fishes, the perches, carps, sal mons. and sturgeons are'present as whole tribes, together with many lesser groups. especially of fresh-water or coast fishes. NOMe the lungfishes are conspicuous absentees. 111 t he class, Aniphillia, the line is drawn at the frog family Cystigna thillm, which is entirely Arctogwan. (;:olow points I he predominance of .1rei fern. which constitute nine-tenths of the anurous population, and are hardly represented in Notogiva. I if tur tles, the presence of Trionychoidea and the ab sence of Chelyilid• are distinctive. Of lizards, exclusively Aretogwal groups are the Lacer! hhe, Zoinoriih•, mong t lie snakes. the viper family is ent i rely A,retogwal, and the crotaline tribe mainly so. Lesser exclu sive groups are the I 'ropeltidw, Nenopelt idle, and many ge»era. Ornithological distinctions may he most easily sketched by saying that Aretog•a possesses no emus or ea OW11 ries: 110 birds of paradise, lyre-birds. cock:11.011., t illa 111011S, h.:1147j 115. mica s.. CIA I fign or many Other, lilt it is rich in game birds, finelies, wood-warblers. and the like. But
perhaps the most striking dilTerence is the pres 0111.0 of the large Arctic tribe of auks, and the like, and the absence of penguins. Among mam mals. also. the most notable feature is the entire absence of edentates, of minint reifies. of mar supials (except one opossum). 14 kepi, 1111 The northern 11 vgion, ever, has the lemurs, the insectivores except the lVest Indian Solenodon, the elephants, rhinoceroses, hy races, horses. deer. giratres, bovines, hyenas, hares, and a variety of other important families; it is, in fact, a. Ileddard points out. t he headquarters of all the Entheria except edentates and marsupials.
12) lluhnrlcc, or Pronince.—In a more restricted and perhaps more usual sense, the term quolaretie' in zo;igeography denotes a circumpolar district formed by the union of the Palaearctic and Nearctic provinces of Selater and \Vallace, elsewhere described. It was long api, telt that the faunal ella•aeleristics of North Arneriea and the northern part of the Old World were not sufficiently distinct to justify their separation into two provinces. Their union under one name was first made by A. Ileilprin, who proposed `Triarctie as the new designation. For this A. Newton suggested the substitution of `Holarctic,' which Heilprin at once adopted. More recently Gadow has used 'Periarctic' as a synonym, on the ground that it is more precise. Its f6mal characteristics are those sketched in the first paragraph, with the omission of such forms as are exclusively Ethiopian (Africa, south of the Sahara) or Oriental (the Asiatic coast and islands south of the Himalayan watershed). The faunal agreement between North America and the northern part of the Old World is greater than any differences. There are few families not represented in both, and the distinctive ani mals are mainly local genera or species, while a great many apparently identical forms occur on both continents, having a circumpolar dis tribution due either to their powers of travel Ot to ancient land connections. Consult: Heilprin, Geographical and Geological Distribution of Ani mals (New York, 1887) ; Newton, Dictionary of Birds (New York, 1396) ; and the authorities referred to under DISTRIBUTION OF ANIMALS. See also NEARCTIC REGION; PALEARCTIC REGION.