124 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



GYMNURA ALBA Giebel. 



1909. Gymnura alba, Lyon, Proc. U. S. Nat. Mus., vol. 36, p. 453, May 27, 1909. 

 Six specimens from the Sempang River, southwestern Borneo. 

 (For a full account of and measurements of these specimens see 

 paper referred to above.) 



In one of them a nearly mature embryo in utero. — W. L. A. 



GALEOPTERUS BORNEANUS, new species. 



Type.— Skin and skull of adult female, Cat. No. 151888, U.S.N.M., 

 collected at Tjantung, southeastern Borneo, January 30, 1908, by 

 Dr. W. L. Abbott. Original number 5775. 



Diagnostic characters. — A medium-sized member of the genus 

 closely resembling the flying lemur from the Malay Peninsula 1 and 

 the one from Bunguran of the Natuna Islands, 2 but skull slightly 

 smaller than that of G. peninsulse, and with distinctly shorter max- 

 illary tooth row and smaller audital bullae; skull and maxillary tooth 

 row about the same general size as in G. natunse, but braincase and 

 interorbital region distinctly broader and nasals more pinched up 

 into ridge. 



Color. — Type: Upper surface of head, neck, body, tail, feet, and 

 outer surfaces of limbs varying shades of gray, produced by irregular 

 mixtures of dirty white and blackish, notably about the shoulders 

 and hips the whitish color darkens to a buff yellow. The usual light 

 spotting is found on the feet, and a rather conspicuous white spot is 

 found on each side of the base of the tail. The outer border of the 

 membrane above is dull chestnut. General color of the entire under 

 parts except chin and throat, varying mixtures and shades of dull 

 tawny ochraceous and clay color; chin similar to upper parts and 

 throat, a gradual blending of the colors of the chin with those of the 

 under parts. 



Skull and teeth. — The skull is of medium size, about equal to that 

 of Galeopterus natunse, but the interorbital constriction is wider, the 

 brain-case decidedly wider, the nasals more pinched up into a ridge, 

 and the rostrum deeper; audital bullae of about the same size, the 

 palate, posterior nares, and interpterygoid space decidedly wider in 

 the Bornean form. Compared with a skull from the Malay Penin- 

 sula, that of the Bornean animal is slightly smaller, with smaller 

 bullae, less inflated mastoids. The teeth have about the same size 

 that the} r do in the Malay form, but the tooth row is shorter. The 

 individual teeth appear slightly larger, but the tooth rows have about 

 the same lengths in the Bornean and Natunan forms. 



Measurements. — See table, page 126. 



i Galeopterus peninsulx Thomas, Ann. Mag. Nat. Hist., ser. 8, vol. 2, p. 303, September, 1908. 

 Selangor-Pahang boundary, Malay Peninsula. 



2 Galeopithecus natunx Miller, Smiths. Misc. Coll., vol. 45, p. 50, November G, 1903, Bunguran Island, 

 North Natunas. 



