CAVY  , a name commonly applied to several

South American rodent animals included in the family Caviidae (see RODENTIA), but perhaps properly applicable only to those belonging. to the typical genus Ca ia, of which the most familiar representative is the domesticated guinea-pig . Cavies in general, the more typical representatives of the Caviidae, are rodents with hoof-like nails, four front and three hind toes, imperfect collar-bones, and the cheek-teeth divided by folds of enamel into transverse plates . The tail is short or rudimentary, the incisors are short, and the outer surface of the lower jaw is marked by a distinct ridge . True cavies, or conies (Cavia), are best known by the guinea-pig, a domesticated and parti-coloured race derived from one of the wild species, all of which are uniformly coloured . They are comparatively small and stoutly built animals, with short, rounded ears and no tail . In habits they are partly diurnal; and live either in burrows among the crevices of rocks, beneath the leaves of aquatic plants in marshy districts, or underneath the floors of outbuildings . Their cries are faint squeaks and grunts . They feed upon nearly all vegetable substances, but drink little . Generally they associate in small societies, and seldom wander far from home . Although the guinea-pig is a fertile breeder, the wild species only produce one or two young at a birth, and this but once in a year . The young come into the world in a highly developed condition, being able to feed them-selves the day following their birth . Cavies are widely distributed in South America, and are represented by several species .

Among them may be mentioned the aperea or restless cavy (C. porcellus or C. aperea) of

Brazil; the Bolivian C. boliviensis, found at great elevations in the Andes; the Brazilian rock-cavy (C. rupestris), characterized by its short blunt claws; and the Peruvian C. cutleri . The latter was tamed by the Incas, and is the ancestor of the guinea-pig . As to the origin of that name, some writers consider it a corruption of Guiana-pig, but it is more probable that the word " Guinea " merely signifies foreign . The guinea-pig is a singularly inoffensive and defenceless creature, of a restless disposition, and wanting in that intelligence which usually characterizes domestic pets, although said to show some discrimination . It is of no particular service to man, neither its flesh nor its fur being generally put to use, while the statement that its presence is sufficient to drive off rats and mice appears to be without foundation . It is exceedingly prolific, beginning to breed at the age of two months; the number of young varying, according to the age of the parent, from four to twelve . It has been calculated that a single pair of guinea-pigs may prove the parent stock of a thousand individuals in a single year . A very different animal is the Patagonian cavy, or mara (Dolichotis pataclsonica), the typical representative of a genus characterized by long limbs, comparatively large ears, and a short tail: The animal is about the size of a hare, to which it approximates in form and habits . It is most abundant in the open districts of Patagonia, but also ranges on to the Argentina Pampas, where it is now scarce . Although occasionally seen in large flocks, the mara is more commonly found in small parties or in pairs, the parties commonly moving in single file . It has a peculiar kind of hopping gait; and is mainly diurnal, in accordance with which habit its eyes are protected by lashes . It lives in a burrow, generally excavated by itself; but when pursued, seeks safety in flight, rather than by a retreat to, its hole .

From two to five young are produced twice a year . A much smaller species, D. salinicola, without the characteristic

black band above the tail, inhabits the salt-plains of Argentina . Maras have been introduced into several British parks . Fossil *pecies of Dolichotis occur in the caverns of Brazil, and also the superficial deposits of Argentina . (R .