Definition: Micromelalephlia is a type of cephalopod, often found in freshwater environments. It consists of two distinct groups: the micromelalephillid group and the micromelalophas group. The micromelalephillid group contains organisms with long, thin bodies that are not typically found in freshwater ecosystems, while the micromelalophas group is characterized by its narrow, cylindrical bodies and a unique structure called a "cyst."