Xingó, Canidé do São Francisco, Sergipe, Brazil | Leito do rio São Francisco represado, formando um canion que compõe o sistema da Usina Hidrelétrica de Xingó, fonte de turismo e de projetos de irrigação do semi-arido
This is the velella (Velella Velella), a small free floating hydrozoan. It's currently the only known species in the genus. They're also known as sea-rafts or by-the-wind-sailors, for the obvious reason that it uses the the "sail" you can see in this image for locomotion. Because of this, they are often found washed up on beaches.