In 1849 he began A Monograph of the Trochilidae or Humming-birds extending to five volumes, the last of which appeared in 1861, and was followed by a supplement by Mr Salvin.
Trochilidae, humming-birds, American.
First in point of importance comes the extraordinarily beautiful family of humming-birds (Trochilidae), with nearly 150 genera (of which only three occur in the Nearctic region) and more than 400 species.
Birds which are indigenous, but extend far into North America: Cathartae, Trochilidae, Tyrannidae.
But the greatest reduction, with only A remaining, is characteristic of such a heterogeneous assembly as Accipitres, Cypselidae, Trochilidae, Striges and Fregata.