Temminck, 1853
Island Flying fox
External characters (Table 6)
This is a considerably smaller species than P. giganteus with an average forearm length of 141.0 mm (135-145 mm). The forehead, cheeks and chin are dark brown; the crown of the head is fawn and the mantle a deeper russet brown. It is paler in the mid-dorsal region, with grey and black hairs intermixed in differing proportions (Phy1). The belly is fawn coloured medially; chestnut on the lower shoulders; dark brown to black on the flanks and around the vent. The claws are less developed than those of P. giganteus and the feet noticeably smaller. The ears are short and broad (Fig. 7) in comparison to those of P. giganteus (PG2), with the tips more broadly rounded off; when laid forward the ears do not reach the eye. The baculum (Fig. 12) is smaller and less evenly semicircular than that of P. giganteus .
Cranial characters
The skull (Fig. 13) with an average condylobasal length of 60.6 mm (59.0-64.1 mm) is smaller than that of P. giganteus . The rostrum is distinctly narrower than that of P. melanotus and the braincase appears narrow in comparison to that of P. giganteus .
Dentition
The dentition (Fig. 14), with an upper toothrow length (C-M2) of 24.0 mm (22.8-25.7 mm) is distinctly less robust than that of P. melanotus , with the cheekteeth noticeably narrower.
Variation
The specimen from the Maldives is referred to P. h. maris . Specimens from Narcondam and Barren Island are provisionally referable to P. h. geminorum ; if they are found to be racially distinct from geminorum , the name satyrus is available.
Taxonomic remarks
Corbet and Hill, 1992 included the taxon satyrus in P. melanotus . They noted that there were close similarities in pelage colour variation between P. m. tytleri , P. m. satyrus , P. m. melanotus and P. hypomelanus geminorum and suggested that P. melanotus and P. hypomelanus are more closely linked than is apparent from Andersen, 1912. However an examination of specimens of all four taxa in The Natural History Museum, London suggests that P. melanotus is a distinct species from P. hypomelanus , with tytleri a valid race in the Andaman Islands. The taxon satyrus is not referable to melanotus but is rather a synonym of hypomelanus , since the skin and skull of the holotype of P. satyrus cannot be differentiated from a series of P. hypomelanus geminorum from the Mergui Archipelago in southern Myanmar.