Altocumulus stratiformis perlucidus undulatus - stratiformis because it occured in a layer - perlucidus because clear sky is visible between elements - undulatus because the elements or rolls occur in a banded or undulating pattern. The smaller striations appear to be a type of pileus. The altocumulus rolls are occuring in a sheared enviroment. Some forced lifting of a shallow humid layer appears to be creating this type of pileus.

Iridescence in small patches and in the 'pileus' can also be seen in some of these images.