(Horsfield, 1855)
Himalayan Whiskered bat; Siliguri bat
External characters (Table 66)
This is a small species with a forearm length (based on extralimital material) of 30.0-31.5 mm. Pelage colour is a uniform dark brown above. The hairs on the ventral surface have dark brown roots and pale brown tips. The muzzle is pointed with a well developed fringe of fine hairs on the upper lip. The ears are similar to those of M. muricola and the feet are not enlarged. The interfemoral and wing membranes are a uniform brown colour and the wings are attached to the base of the phalanx of the outer metatarsal of each foot.
Cranial characters
The skull has a condylo-canine length of about 11.2 mm. The braincase is conspicuously domed, especially anteriorly. In comparison to M. muricola , it is distinctly elevated above the flattened rostrum. When viewed from behind, the braincase is tall in relation to its width; it is almost square in outline; in M. muricola it is compressed and rectangular in shape. The rostrum has a shallow groove in the mid-line and the zygomata are very delicate. The tympanic bullae are well developed. The coronoid process of each half mandible is robust and exceeds the canine in height. It has a vertical anterior border and a shallow posterior border which slopes gently downwards to the condyle.
Dentition
- Upper toothrow length (C-M3) averages 4.7 mm (4.5-4.8 mm). The dentition is very weak. This is especially noticeable in the upper canine which scarcely exceeds the third upper premolar (PM4) in height. Both the first two upper premolars are reduced; the second (PM3) is about two-thirds the crown area of the first (PM2); both are situated in the toothrow. PM2 is not in contact with the third premolar (PM4). The crown area of the molars are greatly reduced throughout. M3 includes a parastyle, mesostyle and three commissures. In general, the upper molars are about half the crown area of those of M. muricola .
- The lower canine is very poorly developed, equal or less in height and crown area to the third lower premolar (pm4). The first lower premolar (pm2) is two-thirds the height of the canine and over half its crown area; the second (pm3) is about half the height and crown area of pm2; it is also situated in the toothrow. m3 is subequal to m2 in size; the talonid is slightly reduced.
Variation
All specimens from the Indian subcontinent are referred to the nominate subspecies M. s. siligorensis .
Taxonomic remarks
As noted in the Taxonomic remarks section of M. mystacinus , following Hill, 1983, the taxon siligorensis is considered specifically discrete from M. mystacinus .