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Show 1876.] MR. E. R. ALSTON ON THE ORDER GLIRES. 81 C. PLATACANTHOMYIN^E, Molars f, divided into transverse laminae. Infraorbital opening typical ; incisive foramina and auditory bullae small. Form myoxine ; fur mixed with flattened spines ; tail densely haired. Indian. Recent genus : - 3. Platacanthomys, Blyth, Proc. As. Soc. Bengal, xxviii. p. 289 (1859). (Characters those of the subfamily.) D. GERBILLIN^E. Incisors narrow ; molars divided into transverse laminae. Infraorbital opening typical; pterygoid fossae short; auditory bullae usually large. Hind limbs elongated; tail long, hairy. Palaearctic, Indian, and Ethiopian. Recent genera :- 4. Gerbillus, Desmarest, Nouv. Diet. d'Hist. Nat, xxiv. p. 22 (1804). Form murine; muzzle pointed; ears moderate, sparsely haired; tail long, hairy, slightly tufted. Skull with occipital region broad; auditory bullae large. Incisors grooved or plain. First molar with three laminae, the second with two, the third with one only. 5. Mystromys, Wagner, Wiegm. Arch. 1841, p. 132 . . (1841). Ears large and broad ; tail moderately long, truncated, not tufted. Auditory bullae smaller. Incisors plain. First molar with three laminae, the second and third with two each ; these are alternated, and the last is very small. 6. Otomys, F. Cuvier, Dents des M a m m . p. 168 . . . . (1825). Ears large, hairy; tail moderate, clad with scales and short hairs, not tufted. Nasal profile more arched than in Gerbillus. Incisors grooved. Molars with their laminae completely separated and united by cement; the third the longest, with from three to seven laminae. 7. Dasymys, Peters, Monatsb. Akad. Berlin, 1875, p. 12 (1875). Ears moderate, hairy ; fur somewhat coarse ; tail moderate, scaly, and sparsely haired. Skull intermediate between Gerbillus and Mus. Lower branch of maxillary zygomatic process produced forward in a hook-shape. Incisors plain. Front molars the longest ; the posterior lamina of the first and the anterior laminae of the second and third upper molars large and complicated. E. PHLOSOMYINJE. Incisors broad; molars divided into transverse laminae. Infraorbital opening typical. Claws large. Indian. Recent genera:- 8. Phlceomys, Waterhouse, P. Z. S. 1839, p. 108 . . . . (1839). Muzzle blunt; lip imperfectly cleft; ears moderate, hairy externally ; tail moderately long, densely haired. Skull ovate ; frontals not contracted, with a rudimentary postorbital process at their junction with the squamosals ; auditory bullae very small. Incisors very broad. First upper molar with three laminae ; second and third with two ; first lower with four, second with three, and third with two laminae. PROC. ZOOL. SOC-1876, No. VI. 6 |