described in a thicker third volume, the cost of which will be proportionately greater, so that the price of the two volumes together will remain unaltered. By this means descriptions of all Indian Passerine birds, which are more numerous than those of all other orders together, and which afford the greatest difficulties in identification, are placed at once in the hands of Indian ornithologists, whilst Mr. Oates's work is kept distinct from that of any other writer. I can only express my regret that Mr. Oates has been unable to finish the work he has so well begun.
The present is the second volume of the 'Fauna of British India' published in the current year, Mr. Boulenger's ’Reptilia and Batrachia' having been issued in August. The only part now wanting to complete the Vertebrata of the Indian Fauna, besides the third volume of Birds, is the second half of the volume containing Mammalia; and this half -volume, the greater portion of which is written, will, I hope, be completed early in 1891. It is not probable that the Birds can now be finished next year, but I propose to undertake the third volume as soon as the Mammalia are completed.
October, 1890.
