The sea angel (Clione limacina) is a winged mollusc, and lives around the world in temperate seas.  I’m fascinated by the way this graceful translucent animal beats its wings and floats through the water.  On the Pacific coast its range is from northern Alaska to northern Mexico.  They can grow to just over three inches (8 cm) long, and blooms of them can occur near the surface in late winter.