1911 Encyclopædia Britannica/Paca

PACA, the Brazilian name for a large, heavily-built, short-tailed rodent mammal, easily recognized by its spotted fur. This rodent, Coelogenys (or Agouti) paca, together with one or two other tropical American species, represents a genus near akin to the agoutis and included in the family Caviidae. Pacas may be distinguished from agoutis by their heavier and more compact build, the longitudinal rows of light spots on the fur, the five-toed hind-feet, and the peculiar structure of the skull, in which the cheek-bones are expanded to form large capsules on the sides of the face, each enclosing a cavity opening on the side of the cheek. Their habits are very similar to those of agoutis, but when pursued they invariably take to the water. The young, of which seldom more than one is produced at a birth, remain in the burrows for several months. The flesh is eaten in Brazil. Males may be distinguished from females by the skull, in which the outer surface of the cheek-bones is roughened in the former and smooth in the latter sex. The paca-rana (Dinomys branicki), from the highlands of Peru, differs, among other features, by its well-developed tail and the arrangement of the spots. (See Rodentia.)