Figure 19. Cambala hubrichti Hoffman (order Spirostreptida), from the southern Appalachian Mountains, North Carolina. Photo by H. Ellis.

Order Spirostreptida (11 families) - gonopods comprised of both leg pairs on segment 7; body generally smooth and cylindrical, 30-90 segments; size varying from narrow, fragile species to huge and robust, including the largest known millipedes (about 28 cm [10 1/2 inches] in length). Occurrence: Western Hemisphere, Africa, southern and southeastern Asia (south of Himalayas) to Japan, Australia. New World occurrence: western Pennsylvania and northern Idaho to northern Florida, the Gulf Coast, and Argentina; Greater and Lesser Antilles. This order includes the only native millipedes in the Hawaiian islands.

Order Polydesmida (about 28 families) - gonopods comprised of anterior legs on segment 7; body usually with 20 segments, occasionally 19, usually with variable "paranota" that impart a flattened appearance and the name "flat-back millipedes"; dorsum varying from smooth and unmodified to highly ornamented with lobes and pustules; size varying from 3-150 mm [over 6 inches]; large forms often highly colorful, with vivid red, orange, blue, and violet pigmentations in spotted or banded patterns. This order has the most species and is only one with cyanide in defensive secretions. Occurrence: Worldwide. A number of species have been widely introduced through human commerce; a few are essentially pan-global and are common in American cities. One of these is a household pest that occasionally undergoes population explosions, in which thousands of individuals overwhelm homeowners. New World occurrence: northern Quebec and southern Alaska to south Florida, the Gulf Coast, and the southern tip of South America; Greater and Lesser Antilles. [see cover]

Order Siphoniulida (1 family) - males unknown; body cylindrical, head prolonged into prominent "beak." Known only from seven females. Occurrence Guatemala; Chiapes, Mexico; Sumatra.

Figure 20. Pseudopolydesmus serratus (Say) from central North Carolina. The ventral view is of a male showing the gonopods replacing the anterior legs on segment 7.