Topography.—In a country so little known to western travellers there is naturally great difficulty in locating the mountains and villages quoted by collectors, when no further indication is given than the sound of the Chinese name. As an instance of this may be mentioned that, of the five or six villages referred to by Dr. Tate, as the localities of his collection of January, 1863, which is now preserved at Kew, not one can be found on European maps. These and other similar place names are quoted in the enumeration of species pending their rediscovery and are included in the index with the note "not yet located." The position of all other places quoted in the list are there explained, further information being added when necessary in the index. Some of the more important localities are shown on the map.

The list of localities cited in the text under each species begins with those in Hongkong and continues with the Hongkong New Territory; then follow the coastal regions, beginning from the east, and finally inland places in order of their remoteness from the coast. The area designated Hongkong refers to the island of that name, which is in one of the numerous groups situated off the south-east coast of China at the mouth of the Canton River. It is about 11 miles long by 2 to 5 broad with an area of some 30 square miles. But the term usually includes the small Kowloon peninsula, a portion of the mainland which approaches closely to the island, and the islets of Stonecutters, Aplichau and a few others, ceded to Great Britain in 1860.

The New Territory, or New Territories as it was originally called, was leased to Great Britain in 1898. It comprises about 300 square miles of the mainland behind or north of Kowloon, as well as several adjacent islands. The largest of the latter, Laotao, is larger than Hongkong Island. The eastern shores of the mainland portion are washed by the waters of Mirs Bay, its western side forming the eastern shore of the Canton River estuary. No special reference is necessary here to the topography of the British territory as excellent maps on various scales are available. Further inland the location of collectors' stations is less easy, but much valuable topographical information has been collected by missionaries and other residents. This and a few small-scale native maps are so far our only sources of information. No general survey with modern instruments has yet been made. The German and French maps, on a scale of 16 miles to the inch, showing the mountain ranges by shading, provide a neat and convenient summary of our present knowledge of the physical features and topography of the province.