Addresses classification, excretory and muscular systems, morphology, behavior, development, and lists of species.

Provides information on characteristics and classification of this species. With photos and references.

Provides information on identifying features and biology of these species. With photos and links.

Contains photos of these species. With background information.

Presents basic information on this animal group. With links and photos.

Contains an abstract and literature cited in article by Lovely, Eric C.

Provides information on morphology and ecology of these species. With photos.

Contains photos of this representative specie. With background information.

Presents overview, phylogeny, and list of orders linking for further details.

Provides information on body size, behavior and diet of these species. With photos.

Contains a taxonomic diagram of this animal class. With references.