Myriapods

The four classes grouped together as "Myriapoda" (Chilopoda, Diplopoda, Pauropoda, Symphyla)are probably no more closely related to each other than to other orders such as Insecta. However the term Myriapoda remains a convenient one to group together these uniramian arthropods with numerous legs (8 or more pairs in adults).

It is often difficult to be clear as to whether myriapods found in or close to the littoral zone are, to use Silvestri’s (1903) terminology, myriapodi halofili genuini i.e. confined to such habitats (obligate halophiles), myriapodi halofili indifferenti i.e. occurring in both terrestrial and littoral habitats (facultative halophiles) or myriapodi halofili accidentali i.e. chance occurrences (accidental halophiles). Such a situation may well be true of all “terrestrial” groups in which some species have invaded the littoral zone. Myriapods are essentially terrestrial groups of arthropods but representatives of all four classes from different orders, families and genera have colonised sea shore habitats and the situation is made more complex by species which appear to be genuini in one region but occur inland in another. The geophilomorph centipede Hydroschendyla submarina, for instance, is only ever recorded from seashores in northern Europe, the Mediterranean and Bermuda and is clearly genuini whilst Pachymerium ferrugineum is clearly indifferenti in much of its range. However, in many cases, where species are described from a single littoral site no such clarity is possible and this list may include some species which may later be considered accidentali.