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Show 1905.] OP THE GENUS RHIXOLOPHUS. 77 metacarpal, as compared with the 4th and 5th; the 5tli metacarpal decidedly longer than the 4tli; &c. Tail a little longer than the lower leg. Plagiopatagium inserted on tarsus. Colour (of a spirit-specimen, unfaded). Fur of upper side a very dark shade of " drab," approaching " Front's brown " ; base of hairs rather more distinctly drab; under side somewhat darker than drab. Skull. Four anterior nasal swellings and two posterior. The four anterior arranged in a transverse row, forming the upper and lateral borders of the nasal opening. Externally these anterior swellings are separated only by extremely faint linear depressions ; internally by three bony lamellae, also easily observable through the thin, transparent outer wall of the swellings. The posterior nasal swellings, situated immediately behind the anterior ones, at the front corner of the orbital cavity, are much lower, slightly concave at summit; three very faint lines divide them, rather indistinctly, into an upper, middle, and lower swelling.-The shape and arrangement of the nasal swellings, as here described, are, roughly speaking, the same in almost all the members of the simplex-group ; there is some variation in the size of the swellings in the different species; but the more noteworthy deviations from the general scheme are two only : Rh. malayanus and Rh. stheno. Postnasal depression triangular in shape, rather long ; the supraorbital crests, which constitute the lateral border of this depression, meeting (and joining the sagittal crest) at a point more or less behind the middle of the orbital cavity. " Supraorbital length " of skull (i. e. distance between the point of junction of supraorbital crests and median anterior point of nasal swellings) greater than extreme width of nasal swellings.-The shape of this part of the skull, as here described, is characteristic of only the four most primitive members of the group (simplex, mega-phyllus, truncatus, nanus). Palatal bridge comparatively long (in antero-posterior direction); measured in the median line equal to about one-third the length of the upper tooth-row ; median anterior point opposite the front of m1, median posterior point opposite the middle of nr. Dentition. As a general guidance : in all existing species of the genus the upper p3 * is completely lost; in all the more primitive * I write the dental formula (excl. of incisors and canines) of a Rhinolophus with the p- m1 lii^ most complete known dentition as follows : p0 p3 Pl m, m„ m3 ^ ^ erlu^ ^ iuSe) " Jordfundne oz nulevende Flagermus fra Lagoa Santa; med Udsigt over Flager-musenes indbyrdes Sbegtskab" ; E Museo Lundii, vol. ii. pt. 1 (1892), p. 56). As already mentioned by Winge, we have no positive proof whether the upper premolar iost in all known species is p3 or p2. For two reasons I regard the former alternative to be the more probable :- (1) In all Rhinolophi, also the most primitive forms, the lower p , is on the point o f being reduced, in the more highly-developed species pushed definitely out to the external side of the tooth-row, in the still higher forms completely lost; it is but reasonable to suppose that the premolar quite lost in the upper jaw of all species corresponds to the premolar which is on the point o f beinq lost in the lower jaw of all species, in consonance with the general rule that the teeth of the upper jaw show a more advanced stage of evolution than those |