Remembering our conclusions as to the early history of the several regions, these facts enable us to indicate, with considerable probability, the origin and mode of dispersal of the cuckoos. They were almost certainly developed in the Oriental and Palæarctic regions, but reached the Neotropical at a very early date, where they have since been completely isolated. Africa must have long remained without cuckoos, the earliest immigration {309}being to Madagascar at the time of the approximation of that sub-region to Ceylon and Malaya. A later infusion of Oriental forms took place probably by way of Arabia and Persia, when those countries were more fertile and perhaps more extensive. Australia has also received its cuckoos at a somewhat late date, a few having reached the Austro-Malay Islands somewhat earlier. The classification of the family is somewhat unsettled. For the American genera I follow Messrs. Sclater and Salvin; and, for those of the Old World, Mr. Sharpe's suggestive paper in the _Proceedings of the Zoological Society_, 1873, p. 600. The following is the distribution of the various genera:-- (2195) _Phænicophaës_ (1 sp.), Ceylon; (2196) _Rhamphococcyx_ (1 sp.), Celebes; (2196) _Rhinococcyx_ (1 sp.), Java; (2196 pt. and 2203) _Rhopodytes_ (6 sp.), Himalayas to Ceylon, Hainan, and Malaya; (2203 pt) _Poliococcyx_ (1 sp.), Malacca, Sumatra, and Borneo; (2197) _Dasylophus_ (1 sp.), Philippine Islands; (2198) _Lepidogrammus_ (1 sp.), Philippine Islands; (2200) _Zanclostomus_ (1 sp.), Malaya; (2201) _Ceuthmochares_ (2 sp.), Tropical and South Africa and Madagascar; (2202) _Taccocua_ (4 sp.), Himalayas to Ceylon and Malacca; (2204) _Rhinortha_ (1 sp.), Malacca, Sumatra, Borneo; (2199) _Carpococcyx_ (1 sp.), Borneo and Sumatra; (2220) _Neomorphus_ (4 sp.), Brazil to Mexico; (2205 2206) _Coua_ (10 sp.), Madagascar; (2207) _Cochlothraustes_ (1 sp.), Madagascar; (2221) _Centropus_ (35 sp.), Tropical and South Africa, the whole Oriental region, Austro-Malaya and Australia; (2213) _Crotophaga_ (3 sp.), Brazil to Antilles and Pennsylvania; (2212) _Guira_ (1 sp.), Brazil and Paraguay; (2209) _Geococcyx_ (2 sp.), Guatemala to Texas and California; (2211) _Dromococcyx_ (2 sp.), Brazil to Mexico; (2210) _Diplopterus_ (1 sp.), Mexico to Ecuador and Brazil; (2208) _Saurothera_ (4 sp.), Greater Antilles; (2219) _Hyetornis_ (2 sp.), Jamaica and Hayti; (2215) _Piaya_ (3 sp.), Mexico to West Ecuador and Brazil; (2218) _Morococcyx_ (1 sp.), Costa Rica to Mexico; (2214) _Coccygus_ (10 sp.), La Plata to Antilles, Mexico and Pennsylvania, Cocos Island; (2227) _Cuculus_ (22 sp.), Palæarctic, Ethiopian, and Oriental regions, to Moluccas and Australia; (2229) _Caliecthrus_ (1 sp.), Papuan Islands; (2230-2232) _Cacomantis_ (15 sp.), Oriental and Australian {310}regions to Fiji Islands and Tasmania; (2233-2237) _Chrysococcyx_ (16 sp.), Tropical and South Africa, the Oriental and Australian regions to New Zealand and Fiji Islands; (2238)