Xerus princeps

DIAGNOSIS. Xerus princeps is similar to both X. inauris and X. erythropus in having lateral longitudinal body stripes (Fig. 1) but is sympatric only with X. inauris. X. princeps and X. inauris are almost identical in appearance, but hairs on the head and lateral hips are white-tipped in X. princeps versus evenly colored along their length in X. inauris, resulting in a more grizzled appearance in X. princeps (de Graaff 1981). Tail hairs are white with 3 black bands in X. princeps as opposed to 2 in X. inauris (Thomas 1929). Incisors are yellow to orange in X. princeps, not white as in X. inauris (Herzig-Straschil et al. 1991; Thomas 1929). Ossa nasalia of X. princeps are significantly narrower (mean 5 7.8 mm 6 0.28 SD, n 5 22) than those of X. inauris (9.0 6 0.71 mm, n 5 157) and do not widen in the anterior area (Herzig-Straschil et al. 1991; Thomas 1929; Fig. 2). Skulls of X. princeps (n 5 22) are significantly larger than those of X. inauris (n 5 157) in condylobasal length (54.6 mm 6 1.38 SD versus 53.1 6 1.82 mm), occipitonasal length (58.2 6 1.53 versus 56.4 6 1.99 mm), interorbital width (17.9 6 0.83 versus 17.0 6 0.86 mm), postorbital width (22.5 6 0.39 versus 21.4 6 0.84 mm), and incisor thickness (3.9 6 0.26 versus 3.6 6 0.23 mm— Herzig-Straschil et al. 1991). Ratio of orbital diameter to the occipitonasal length (less than one-third in X. inauris; more than onethird in X. princeps) has been used as a discriminating feature; however, this distinction was not supported in a detailed comparison of the skulls of the 2 species (Herzig-Straschil et al. 1991). X. princeps is heavier (612.4 g 6 94.8 SD, n 5 7) than X. inauris (523.8 6 50.7 g, n 5 7—Haim et al. 1987).