Acerodon, Jourdan, 1837

Andersen, Knud, 1909, IV. — Notes on the genus Acerodon, with a synopsis of its species and subspecies, and descriptions of four new forms, Annals and Magazine of Natural History, 8 th series 3, pp. 20-29 : 20-24

The Genus Acerodon .

Type.— Pteropus jubatus, Eschscholtz.

Species.— Six (nine recognizable forms), viz. A. mackloti (three subspecies), gilvus , celebensis> hurnilis, lucifer , jubatus (two subspecies).

liauye.— Timor group (Timor, Flores, Alor, Sumba); Celebes group (Celebes, Selayar); Talaut Islands; Philip ­ pines %.

Differential characters.— Acerodon differs from Pteropus by the combination of the following dental characters: (1) Poste ­ rior basal ledge of, and w2 extending along inner base of teeth as a broad, sharply defined shelf; this character is sufficient to distinguish Acerodon from any species of Pteropus , except Pt. anetianus , which possesses a perfectly similar inner basal ledge in the same teeth, but in every other respect is closely allied to the genuinely Pteropine Pt. samoënsis : (2) a well-developed antero-internal basal cusp in p* and m1 (a similar, but smaller, antero-internal cusp developed in p 3 of most species and in p% of A. humilis , jubatus , and liicifer) • acorresponding cusp indicated in certain species of Pteropus , butneveraswell developed and sharply differentiatedasin Acerodon : (3) molariform teeth above and below h>4, m \pi} ???2) rather shorter and broader, and main cuspswithmoretrenchantedges: (4) m2 rather less reduced: (5)upperincisors slenderer and more acutely pointed %.— Skull and external characters not differing.from those of Pteropus .

Originaldescription ofgenus.— Palmer f gives as primary reference for the genus Acerodon, Jourdan , the “Ann. Sei. Nat., Paris,2 esér.,viii, Zool.369-370, Dec. 1837,” and as secondary reference the “ Comptes Rendus, Paris, vi, 3, 1838.” To thisit must be remarked, first, that these two papersgive, theoneexclusively,theother chiefly,F. Cuvier’s “Rapport ”andcritical remarks on a memoir by Jourdan, andthattherefore,reallyaswell as formally, not Jourdan but F.Cuvier is the author of the two papers referred to by Palmer;second,thatin both of these papers the name of the presentgenusoccurs only in its French form ( Acérodon ), and therefore cannot, technically, date from these papers;.third, thatprima facieit appears unlikely that F. Cuvier’s “ Rapport,” which was read before the Paris Academy, should have been published earlier in the ' Annales des Sciences Naturelles ’than in the 1Comptes Rendus’ of the meetingsofthe Academy. In these circumstances I have had to trace the history of Jourdan’s paper and F. Cuvier’s report, which appears to be as follows:—

(1) “ 9 Oct. 1837 C. 11. Ac. Sci. Paris, v. pp. 521-524. This is Jourdan’ s original paper. It contains descriptions of two new genera of mammals (Heteropus and Neloinys} and five new species (lleteropus albogzdaris, Nelomys brasilieusis, JIcdmaturus irma, llydromysfulvoqaster, and Paradojurus Philippinensis). No reference to Acerodon . The paper was read before the Academy on 9 Oct. 1837, and presumably published very soon after.

(2) “ 14 Oct. 1837 ”—L’ Echo du Monde Savant et L 'Hermès, iv. no. 275, p. 156. Jourdan describes ‘‘three ” new genera, Aielomys (sec above), Acerodon , and Ileteropus (see above). 'This is apparently the earliest description of the genus Acerodon † (not known to Palmer). The issue of the weekly periodical ‘ L’ Echo ’ in which it appeared is dated “ Samedi, 14 octobre 1837,” and was very likely published on that day.

(3) “Nov. 1837 ”—L ’Institut, v, no. 221, p. 351. Reprint of no. (1), supra.

(4) “ 2 Jan. 1838 ”—C. R. Ac. Sci. Paris, vi. pp. 2-6. F. Cuvici’ s “ Rapport sur u i mémoire de M. Jourdan, de Lyon, concernant quelques mammifères nouveaux.” This is Palmer’ s secondary reference. Author, F. Cuvier, not Jourdan; no quotations of Jourdan’s own words; z4cero</on occurs only in the French form, 11 Acérodon .” The meeting was held on 2 Jan. 1838, the “ Comptes Rendus ” presumably published a few days. —It appears rather strange that Cuvier ’s Report on Jourdan ’s paper contains remarks on Aeérodon, whereas Jourdan ’s original paper, as printed in the “ Comptes Rendus ” (see no. (1), supra), has no reference to this genus. The explanation may be this: Cuvier ’s remarks on Acérodon are not very favourable for its validity as a distinct genus; as Cuvier, together with Duméril, was the Academy ’s ‘'Commissaire” for zoological papers, he may (privately) have informed Jourdan of this opinion, and Jourdan therefore have withdrawn the description of Acero ­ don from the paper laid before the Academy, but almost simultaneously published it in the “Echo ” (no. (2), supra). But this is, of course, only conjecture.

(5)After 5 Feb. 1838—Ann. Sci. Nat. (2) viii. Zool. pp. 367-374. A reprint of no. (4), supra, but with the addition, in footnotes, of quotations from Jourdan ’s original paper, these quotations, taken together, amounting to a com ­ plete reprint of no. (1). This is Palmer ’s primary reference, evidently because this number of the ‘Annales ’ is dated December 1837; but since it contains a paper read before the Paris Academy on Feb. 5, 1838, it must have been pub ­ lished after this date.

Principal subdivisions of genus.— The six species of Acero ­ don recognized in this paper fall into two natural sections, the one confined to the Timor and Celebes groups, the other to the Talaut and Philippine Islands. The three species of the former section are more primitive, in so far as is typical Pteropine, without antero-internal basal cusp; the ears are relatively longer and the colour of the fur pale above and beneath. The two species inhabiting the Timor group, viz.

A. nia :kluti (Timor, Flores, Alor) and A. gilvus (Surnba) , are closely related, differing chiefly in size, whereas the Celebean speeies ( A. cdebensis ) is characterized by its much weaker dentition. The three species of the latter group are mure specialized in having a distinct antero-internal basal cusp in /⅛; the ears are relatively shorter, the colour of the fur much darker; in general aspect the coloration of these species is much nearer to that of an ordinary Pieropus: head, back, and underparts dark, mantle paler. The single species of this group inhabiting the Talaut Islands ( A. humilis ) is easily recognizable by its small size; externally it is much like certain dark-coloured forms of Pteropus hypomelanus ; the two Philippine species ( A. jubatus and lucifer ) are chiefly characterized by their larger size and strikingly pale-coloured nuchal patch; inter se, they differ only in size.

Synopsis of Species and Subspecies.

I. No antero-internal basal cusp in p3; ears longer than muzzle (front of eye to tip of nose); pale-coloured forms: back and underparts approximately mars-brown or vandyckbrown, lightened with golden buffy, head and mantle essentially buffy. (Timor and Celebes groups.)

a. Dentition heavy: wP,length (antero-poste ­ rior diameter of crown) 5'6-6 mm.; skull, total length 66-72 mm. (Timor group.)

a1. Larger: skull, total leDgth 69-72 mm.; forearm 139-156 mm. (Timor; Flores; Alor.)...................................................... 1. A mackl o ti.

a2. Forearm about 139-146 mm.

«3. Underside of body rather thinly sprinkled with buffy hairs. (Timor.) 1 a. A. m. mackl o ti.

Z/3. Underside of body thickly sprinkled with buffy hairs. (Flores.).......... 1 I. A. m.Jloresii.

b2. Forearm about 156 mm. (Alor.). ... 1 c. A. m. alorensi».

b1. Smaller: skull, total length 66 mm.; forearm 135 mm. (Sumba.).............. 2. A. gi lv us.

b. Dentition much weaker: m1, length 4 "-5 mm.; skull, total length 62'5-63 mm. (Celebes group.) ...................................... 3. A. celeben s is.

II. A distinct antero-internal basal cusp in p t; ears shorter than muzzle; dark-coloured forms: back and underparts seal-brown or burnt umber, more or less sprinkled with pale hairs; mantle chestnut or dark ciunamon-rufous. (Talaut Is.: Philippines.)

c. Small: forearm about 140 mm.; no buffy nuchal patch. (Talaut Is.)...................... 4. A. humilis .

d. Large: forearm 165-205 mm.: a buffy nuchal patch strongly contrasting with dark mantle and sides of neck. (Philip ­ pines.)

c1. Forearm about 165 mm. (Panay.) .... 5. A. lucifer .

d1. Forearm 182-205 mm. (Philippines generally.).............................................. 6. A.jubatus .

c2. Averaging smaller: forearm 182-198 mm. (Philippines north of Min ­ danao.) .............................................. 6 a. A.j. jubatus .

d2. Averaging larger: forearm about 205 mm. (Mindanao.) .................. 6 b. A.j. minda n e nsis.