Fam. 1. Leporidae.—This family is distinguished from the Lagomyidae by the long ears, by the tail, which is present, though short, and by the longer limbs. There are six teeth belonging to the molar series in the upper jaw, and five of the same in the lower. The clavicle is imperfect.
The longest known genus of this family, Lepus, was, until the quite recent discovery of Romerolagus, the only genus. It is of universal range, excepting Australasia and Madagascar, and consists of about sixty species. These are the Hares and Rabbits, to the former being assigned the longer-limbed forms.
As every text-book of zoology contains a more or less elaborate account of the structure of the Common Rabbit, and as there is but little structural difference between the members of the genus, a short account of the generic peculiarities of Lepus will suffice here. The fore-feet are five-toed, the hind-limbs four-toed. The hairy integument enters the mouth cavity, and the inside of the cheeks have a hairy covering. The soles of the feet are, moreover, hairy. The maxillary bones are curiously sculptured.
Fig. 246.—Lepus cuniculus. Skull. A, Lateral view; B, ventral view. ang.pro, Angular process of mandible; as, alisphenoid (external pterygoid process); aud.me, external auditory meatus; b.oc, basioccipital; b.sph, basisphenoid; cond, condyle; cor, coronoid process; fr, frontal; int.pa, inter-parietal; ju, jugal; lcr, lachrymal; max, maxilla; nas, nasal; opt.fo, optic foramen; o.sph, orbitosphenoid; pa, parietal; pal, palatine; pal.max, palatine plate of maxilla; pal.p.max, palatine process of premaxilla; par.oc, paroccipital process; peri, periotic; p.max, premaxilla; pt, pterygoid; p.t.sq, post-tympanic process of squamosal; s.oc, supraoccipital; sq, squamosal; ty.bul, tympanic bulla; vo, vomer; zyg.max, zygomatic process of maxilla. (From Parker and Haswell's Zoology.)
The Common Rabbit, L. cuniculus, differs from the Common Hare in the comparatively shorter ears and legs. The ears have not, to so marked a degree, the black tips of those of the Hare. The animal, moreover, produces naked young, and lives in burrows of its own excavation. A difference in the structure of the caecum, which distinguishes the Rabbit from the Hare, has been
pointed out by Professor W. N. Parker.[[363]] These differences have led some to approve of its separation from the Hares into a genus Oryctolagus. This animal is believed to be an introduced species, and to have been brought by man into these islands. Its original home is the Spanish Peninsula, the south of France, Algiers, and some of the Mediterranean islands. Mr. Lydekker thinks that the only other species of Lepus which can be considered to be a "Rabbit" is the Asiatic L. hispidus.
Of Hares there are two species in this country. The Common Hare, L. europaeus (the name L. timidus seems to be really applicable to another species to be referred to presently), extends all over Europe excepting the extreme north of Russia and Scandinavia. It is not known in Ireland, and, curiously enough, attempts to acclimatise this animal in that island have failed—a state of affairs which contrasts with the fatal ease with which the Rabbit has been introduced into Australia. Ireland has, however, the Variable Hare, L. timidus (also called L. variabilis), a species which is common in other parts of Europe, and which extends as far east as Japan. This species differs from its ally by the fact that it often turns white in winter with the exception of the black tips to the ears. In Ireland this change does not always occur; but Mr. Barrett-Hamilton has commented upon the fact that Hares of this species do change on Irish mountains. It appears that in this animal the change from the winter to the summer dress is accomplished by the actual casting off of the white hairs and their replacement by a fresh growth of "blue" hairs. A similar change occurs in the American L. americanus.
Dr. Forsyth Major has noted the fact that the various species of Hares can be distinguished by the condition of the furrows upon the upper incisors. Thus two African species, L. crawshayi and L. whytei, are to be separated by the fact that in the former the incisors are quite flat, whereas in L. whytei the groove is more prominent and there is a second shallow furrow.
The genus Romerolagus[[364]] is quite a recent discovery. It occurs on the slopes of Popocatepetl in Mexico; it has the general aspect of the last genus, and is spoken of as a "Rabbit." It inhabits runs in the long grass which clothes the sides of the