(FIGS 7, 9, 13; TABLES 3, 4, 6)

Holotype: FMNH 211323, an adult male with slightly worn molars (age class II; see Methods and Materials), prepared as a round skin, skull and body embalmed in formalin and now in 70% ethanol, and frozen tissue (liver); collected by M. J. Munissi (original field number W.T.S. 10842). The condition of the skin, skull and preserved post-cranial body are good.

Paratypes: We designate as paratypes three females and four males, FMNH 211131, 211132, 211134, 211322, 211327, 211328 and 211332, all collected at two localities on the Ngorongoro Crater rim in 2010 (see Type locality). All paratypes are preserved as skins, skulls and fluid-preserved post-cranial bodies, with the exception of FMNH 211134, which is preserved as a skin, skull and post-cranial skeleton. See Appendix for additional specimens examined.

4.60; BW: 6.25; NW: 2.00; GW: 9.75; HBC: 6.46; I 3 -W: 0.70; CW: 0.76; M 3 -L: 1.39; M 3 -W: 0.67; MP: 0.94; MI: 13.26; LTR: 8.42.

Diagnosis: Crocidura mdumai is a medium-sized, but robust shrew with a head and body length of 76– 91 mm, tail of 52–65 mm and mass of 7.3–9.6 g (Table 3). It is smaller than any of the other species of this study, except for C. newmarki. It is the smallest of any of the specimens with low levels of pilosity on the tail (Table 6). There is low pilosity on the proximal 43% of the tail (which is 70% of the length of head and body and slightly bicoloured). The long bristles (4 mm) at the base of the tail are translucent; the rest of the tail is covered in short, dark brown applied hairs. The dark brown pelage of the dorsum contrasts slightly with the dark grey of the venter. The hairs of the back are 5 mm in length. The dorsal surfaces of both the front and the back feet are paler than the rest of the body. The longest vibrissae emanating from the snout are 19 mm in length.

The skull is smaller and rounder with less angular anterior corners of the braincase than in those of any of the other species considered in this study (Fig. 13; Table 4). The lateral profile of the skull exhibits a depression between the braincase and the rostrum, which has a slightly rounded lateral profile. The first upper incisor is short and slender (Figs 9, 13), and the upper canine is longer and broader than the third upper incisor.

Type locality: Tanzania, Arusha Region, Ngorongoro District, Ngorongoro Conservation Area, Ngorongoro Crater rim, near Pongo Ranger Post, 3.24407°S, 35.64040°E, 2064 m a.s.l. Paratypes were collected at this locality (FMNH 211322, 211327, 211328, 211332) and: Tanzania, Arusha Region, Ngorongoro District, Ngorongoro Conservation Area, Ngorongoro Crater rim, near Lamala Gate, 3.14255°S, 35.68669°E, 2372 m a.s.l. (FMNH 211131, 211132, 211134).