[2] Centipedes in this genus feature elongate heads, elongate forcipules with denticles, scattered coxal pores, and few sternal pores, if any; the intermediate part of the labrum is narrow and has no denticles.

[3] The Australian species Pachymerinus froggatti is notable for its relatively small size, measuring only 28 mm in length.

[4] The larger Chilean species P. porteri measures 46 mm in length but can have as few as 47 leg pairs (47 to 49 in males, 47 to 51 in females),[5][6] the minimum number recorded in this genus.

The Chilean species P. pluripes measures only 32 mm in length but can have 79 or 81 leg pairs,[5][6] the maximum number recorded in this genus.

The Chilean species P. canaliculatus is known from a female specimen with 75 leg pairs and is notable for its large size, measuring 75 mm in length.