DIPLOPODA (millipedes) > POLYDESMIDA (flat-backed millipedes) ›> Polydesmidae

As previously noted, it is not possible to reliably identify Polydesmus species from photos as the four normally considered species are all superficially similar and, as such, can only be distinguished by close examination of the genitalia.

The four species are Polydesmus angustus, P.coriaceus, P.denticolis and P.inconstans. For completeness, there's actually a further species P.testaceus, which is rare and can effectively be discounted. I believe that any species I find locally will either be Polydesmus angustus or P.coriaceus as the other two have not been recorded from my general area. That said, they're still possible, particularly P.denticollis.

Whilst they have all been found in varied habitats, each species has strong associations with particular places with Polydesmus angustus favouring woodland, P.coriaceus cultivated land, grassland and waste ground, P.denticolis wetlands, and P.inconstans sand dunes and grasslands. Although I catalogue them all as Polydesmus sp., I like the alternative approach of referring to the most likely species based on habitat, which in most cases will be Polydesmus cf.angustus and, in fact, the first of the individuals featured below that I photographed at Kitt's Grave, was identified as such by a leading authority on these species due to the visible gonopods.

The final photos include two juveniles, which have around 16-18 body segments rather than the full quota of 20 that can be counted on the adults.