Hi! I am a new user here. My friend suggested this forum since he believe that I could get help from here. A while ago, I was reviewing my references on the Philippine kingfishers. While scanning some journals, I noticed that there was a changing of taxonomic names on kingfishers. In 1836, Swainson introduced a genus in his book "On the natural history and classification of birds", called the Alcyone: it is described to have traits similar from the Alcedos but distinguished of possesing only three toes. Early 1860's, the behavior from the Alcedinidae were little known of, especially on the small kingfishers i.e., Alcedo and Ceyx. From what I read, ethologically, Ceyces were considered terrestrial by nature. Alcedos on the other hand, spend most of their time on aquatic habitats. They are morphologically distinct by toe count, three for Ceyx and four on Alcedo. It became the common knowledge from both genus. Until the discovery of the aquatic yet three toed kingfishers, and one of these are the C. cyanopectus, C. argentata, C. flumenicola and C. nigrirostris. The "A Manual of Philippine Birds" by McGregor (1909), followed Sawinson's naming. Hence, the aforementioned species were known as Alcyone. But after reading recent papers on kingfisher phylogeny, like Andersen et al. (2018), I think, taxonomist no longer consider Alcyone as a valid category. If I am right, what could be the reason? Maybe it did not abide with ICZN rules?