(K. Andersen, 1911)
Hill Long-tongued Fruit bat
External characters (Table 14)
With an average forearm length of 47.3 mm (44-52 mm), this is a much smaller fruit-bat than Eonycteris spelaea (ES1). The external tail is rudimentary or absent (MS2). The muzzle is elongated and slender and exhibits a marked adaptation to nectar feeding (MS1). The ears are of medium size, a uniform brown and with narrowly rounded tips and small antitragal lobes. The pelage is soft and fine. It is longer than that of Eonycteris . On the dorsal surface, it is a rather uniform clay brown, with the hair bases paler. On the ventral surface, it is buffy brown. Hairs are present on the upper surface of the tibiae; the forearms, above and below, and the inner part of the wing membranes. The interfemoral membrane is also thickly covered in short hairs, above and below, and is reduced and narrow in comparison to that of Eonycteris spelaea . Males are without glandular hairs. The calcars are very reduced and the wing membranes are inserted on the base of the first phalanx of the fourth toe. The third and fifth metacarpals of each wing are about equal in length, whereas in Eonycteris the fifth is distinctly shorter. There are eight undivided palatal ridges, of which five are interdental (Andersen, 1912, Fig. 72b).
Cranial characters
The skull (Fig. 35), with an average condylobasal length of 26.9 mm (26.6-27.1 mm) is much smaller and more delicate than that of Eonycteris spelaea (Fig. 32). The rostrum is relatively longer and narrower and the premaxillae project further forwards. The braincase is more strongly deflected downwards so that the alveolar line projected backwards passes above the lambda. The postorbital processes are weakly developed and the low temporal ridges are more widely separated on the vault of the braincase behind them. The weak lambdoid crests just overhang the vertical supraoccipital. The infraorbital canal is relatively long, its anterior opening is above the middle of M2; in Eonycteris , the short canal opens above M1. The mandible (Fig. 35) is more slender and delicate than that of Eonycteris (Fig. 32), the horizontal ramus of each half has a distinct curvature, it is concave below, convex above; in Eonycteris it is straight. In lateral view, the symphysis has a distinctly squared outline; in Eonycteris , it is sloping. The angular process is rounded and broader than that of Eonycteris ; the coronoid is small, with a narrow tip.
Dentition
- Upper toothrow length (C-M2) averages 8.7 mm (8.6-8.8 mm). The teeth (Fig. 34) are much reduced in comparison with Eonycteris spelaea (Fig. 31), with the premolars and molars notably narrow and linear. The upper incisors (I2 and I3) are small and subequal, with a wide gap between the inner pair. The upper canine has a deep antero-internal groove. The first upper premolar (PM2) is relatively larger than that of Eonycteris . The posterior upper cheekteeth are all notably narrow and low crowned, with the cusps and median grooves scarcely evident in the third upper premolar (PM4), M1 or M2. M2 is relatively long, subequal with or even exceeding M1 in size; in E. spelaea , M2 is about half the crown area of M1.
- In the mandibular dentition, the inner pair of lower incisors (i1) are more widely separated than in E. spelaea . The second incisor (i2) is distinctly larger than the first (i1). The lower canine is slanted outwards. Like PM2, the first lower premolar (pm2) is relatively large. m3 is about three-quarters of the length of m2.
Variation
All specimens from India are referred to M. s. sobrinus . Andersen, 1912 noted that there is no difference in colour or in the development of the fur on the neck between the sexes. Skull size is larger in males.