or flattened spines, which form the whole covering of their bodies, and are not intermingled with ordinary hairs. The habits of most species are strictly terrestrial. They vary in size from the relatively small long-tailed porcupine with body lengths of 27.9 to 48 cm, and a weight of 1.5 to 2.3 kg, to the much larger crested porcupines, which are 60 to 83 cm long, discounting the tail, and weigh from 13 to 27 kg.

The various species are typically herbivorous, eating fruit, roots, and bulbs. Some species