Linnaeus, 1758
Particoloured bat
External characters (Table 86)
This is a medium to small species with an average forearm length of 44.2 mm (42.0-45.5 mm) in extralimital specimens. The ears are short; the anterior and posterior borders are smoothly convex and the tips broadly rounded (Fig. 182). The tragus of each ear is small, short, blunt and rounded. The pelage is characteristically coloured. On the dorsal surface, the hair roots are a deep chocolate brown; some of the tips are also dark, others are pale buffy brown. In consequence, the head, shoulders and back appear 'frosted' with pale hairs. On the belly the hair tips are pale but the roots are dark; the hairs on the throat and inner thighs are pale throughout their length. The membranes are mid-brown; the upper interfemoral membrane is lightly haired adjacent to the body. The tibiae are short and the wings are attached to the base of the phalanx of the outer toe of each foot. The tail is long, with the tip slightly extruded from the interfemoral membrane. The lips and face are naked, brown in colour and with the nostrils outward facing. The penis is black, long and slender. There are two pairs of nipples, 4-5 mm apart (Rydell and Baagøe, 1994).
Cranial characters
The skull (Fig. 183) has a condylo-canine length of 15.0 mm (based on one extralimital specimen). In lateral profile, the skull appears flattened (although not as marked as Tylonycteris (Fig. 191) with the braincase only slightly taller than the rostrum; the dorsal profile is virtually straight from the nares to the lambda. There is no sagittal crest and the lambdoid crests are low. The rostrum is robust, broad and flattened with concavities on each side between the nares and the lachrymal region. The nasal notch is deep and V-shaped. The zygomata slightly exceed the braincase in width; there is a small dorsal process on each jugal bone. The palate is concave and the mesopterygoid space is broad. The tympanic bullae are not greatly enlarged and in consequence the basioccipital is relatively broad. In each half mandible, the coronoid process is short with the posterior border declining gently to the condyle; the angular process is small.
Dentition
- Upper toothrow length (C-M3) averages 5.2 mm (4.9-5.5 mm). The first incisor (I2) is bicuspidate with the secondary cusp subequal to the first. The second incisor (I3) is smaller and with one cusp; it is not in contact with the upper canine which is unicuspid and with a well defined cingulum. The small upper premolar (PM2) is absent (Fig. 184). The large upper premolar (PM4) is in contact with the canine; it has a well defined antero-medial cusp. M1 and M2 are of the normal insectivorous type and are about equal in crown area. M3 is two-thirds the crown area of M2; it is less reduced than that of Eptesicus (Fig. 175).
- In the lower dentition, there are three incisors which are slightly overlapping; the third (i3) is in contact with the relatively small lower canine. The first lower premolar (pm2) is situated in the toothrow; it is compressed between the larger second premolar (pm4) and the posterior cingular cusp of the canine. m1 and m2 are about equal in crown area; in m3, the talonid is more equal to the trigonid in crown area (Fig. 184) (in Eptesicus it is distinctly smaller Fig. 175).
Karyology
2N= 38, FN= 50; among the autosomes, six pairs are large and metacentric, one pair is small and submetacentric, nine pairs are acrocentric and two pairs are dot-like and acrocentric (Heller and Volleth, 1984; Zima, 1978).
Variation
Specimens from Pakistan are provisionally referred to V. m. murinus (Wallin, 1969).