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Show united at the close of the Miocene, descended into the latter area. If so, it presents a striking parallel to that of the Camel family, which was represented by many genera, now extinct, in North America during the Tertiaries, from the Lower Oligocene upwards, entered the Old World, where it is now represented by the Camels, and South America, where the Llamas still exist and extend principally along the mountains far to the south into Patagonia. Here again, as in other cases, the exact parallelism between the Mammalia cited and the Spiders fails apparently only on account of the survival of the latter and the extinction of the former in the area of their origin. To pursue this subject further, and take all the families and genera of Spiders into consideration, would require a special volume. Enough, however, has been said to show that the suggestions put forward to explain the distribution of other groups of animals apply also to the distribution of Spiders. N ote.- During the passage of these pages through the press, Simon has issued two papers (Bull. Mus. d'Hist. Nat. 1902, pp. 595-598; Ann. Soc. Ent. Belg. xlvii. pp. 21-23, 1903) containing descriptions of the following new genera of Mygalo-morphae:- Dipluridae.-Entypesa, allied to the Australian Ixamatus: Madagascar. Cyrtaucheniidae.-Diadocyrtus, allied to the Ceylonese Scalido-gnathus; Genysochcera, near Genysa : Madagascar. Ctenizidae.-Hebestatis, near Pachylomerus : California. Migidae.- Calathotarsus, near the New-Zealand Migas : Chili. Pcecilomigas, near Moggridgea : S. Africa. Barychelidae.-(Barycheli) Zophoryctes, allied to the Australian Trittame ; (Diplothelae) Cestotrema, Acropholius : Madagascar. The chief feature of interest is the six new genera from Madagascar, two of which are related to Australian forms, one to a Ceylonese genus, one to a previously known Mascarene genus ; the remaining two belonging to the Diplothelae, hitherto represented by two genera, one from Madagascar, the other from Ceylon and India. Reference may also be made to the new Chilian genus of Migidae, which I have already mentioned (p. 365), 3flR ON THE GEOGRAPHICAL DISTRIBUTION OF SPIDERS. [Apr. 21. |