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Show 214 MESSRS. BLANFORD AND DRESSER ON [Apr. 21, showing us every possible attention, and affording us all the assistance in their power on the occasion of our visits to their Museums, most kindly allowed us to take away typical specimens for comparison. To Dr. Finsch we are still further indebted for his having lent to us the whole of his manuscripts relating to Saxicola and its allies, containing most valuable notes and identifications. Besides the museums above mentioned, we have visited those of Paris and Frankfort, and examined the fine series of skins in the British Museum. So far as regards the species of the genus found in the Palsearctic region, the numerous described types which we have had the advantage of examining, and the extensive series of specimens which we have been able, by the kindness of our friends, to compare, have given us great advantages in the study of the different forms, the majority of which, moreover, had been personally collected by one or the other of us in different parts of Europe, Persia, India, or Abyssinia. W e feel far less confidence in our determinations of the South-African Saxicola, both because they are less known to us, and because many of the species, founded on figures and descriptions in the works of the older authors, the types of which are unknown, render identification most difficult. This is especially the case with the species usually known as S. monticola, Vieill., S. cinerea, Vieill. (S. tractrac, Boie), and their allies; and we think it not improbable that some forms, which, for want of sufficient information, we have kept distinct, may be merely different phases of the same species, the distinctions being due to age or sex. It is exceedingly difficult to define accurately the limits of the genus Saxicola, and to decide which of the numerous genera into which it has been divided by systematists are really entitled to separation. It is almost impossible to express in words the distinctions between generic groups which, although the typical forms are well marked, are connected by so many links as those which are fouud in the Saxicolina and other subdivisions of the great natural family which comprises the Thrushes and Warblers. In the genus Saxicola, as defined by us, we have species which seem nearly as closely allied to Pratincola, Ruticilla, Thamnolaa and Monticola as they are to Saxicola oenanthe. There is no important characteristic structural distinction, so far as we know, between several of these allied genera. If any character is more constant than the rest in Saxicola, it is the pale or white coloration of the feathers at the base of the tail; yet we feel obliged to admit some species in which this is wanting, and to omit others which exhibit it. In the forms which we include, besides the species closely allied to Saxicola cenanihe, are those for which the generic name Dromolaa was proposed by Cabanis (the type being S. monticola, Vieill.), and those referred to Campicola of Swainson (type S. pileata, Gm.). At the same time we consider that Pratincola (type P. rubetra, L.), which has muscicapine affinities, Cercomela (type C. melanura, Riipp.), which leads to Ruticilla, Agricola (type A. infuscatus, |