EHIZOMYS. 



327 



and in the ridges from the external angle of the frontal being divergent from each 

 other as far back as the occipital ridge, whilst in R. pruinosus they are confluent 

 at the anterior extremity of the parietals. It differs from H. sumatrensis, Eaffles, 

 in its less expanded frontal region, in the greater contraction of the fronto- 

 parietal area, which is much further forward than in that species, and the much 

 . narrower and less massive character of the skull. In H. sumatrensis, HaflB-Cs, the 

 greatest breadth across the zygomatic arch considerably exceeds the distance between 

 the anterior border of the premaxillaries and the hinder margin of the articular 

 surface for the lower jaw, whilst in H. pruinosus, Blyth, it may fall short of that 

 interval, but never exceeds it. The area behind the premaxillary foramina is 

 much more concave than in H. sumatrensis, Hafiles, and the palate of that 

 species is concave and the posterior nares more expanded, but the palatine is 

 in the same plane with the maxillaries. The nasals in H. sumatrensis are pointed 

 posteriorly, with the maxillo-premaxiUary suture some distance anterior to the 

 extremities, and they are much more laterally expanded than in H. pruinosus, Blyth, 

 and the sides of the osseous muzzle of the former are vertical from a ridge external 

 to the nasals, whereas in H. pruinosus the ridge is absent, and the sides of the 

 muzzle are convex. In these latter details regarding the muzzle, B. hadius, Hodg., 

 B. minor. Gray, and B. sinensis. Gray, agree more with this species than with 

 B. sumatrensis. The alveolar border is longer in B. pruinosus than in the latter, 

 and the teeth are larger. 



This species does not appear to attain to the same size as B. sumatrensis, Kaffles, 

 but it greatly exceeds the dimensions of B. badius, and of course is greatly larger 

 than B. minor. Gray. 



Measurements of skulls of J and $ B. pruinosus, Blyth, and B. badius 

 Hodgson : — 



Length, from inferior margin of foramen magnum to tip of preniasillas 

 Greatest breadth across zygomatic arch ....... 



Breadth of muzzle at anterior margin of lower border of infraorbital foramen 



„ across froutals at external orbital angle 



„ „ frontal contraction 



„ „ inner borders of infraorbital foramina .... 



„ between upper borders of auditory opening ..... 

 Length of palate, posterior surfaces of incisors 



„ of alveolar border, outer margin 1st to 3rd molar .... 

 Breadth of palate between inner margins of 2nd molars .... 



„ between paroccipital processes 



Greatest breadth across posterior aspect of skull . . . 



R. pruinosus. 

 6 



Inches. 



2-60 

 1-97 

 0-63 

 0-83 

 0-47 

 0-51 

 1-22 

 1-46 

 0-53 

 0-17 

 0-87 

 1-30 



R.prumosus. 

 ? 



Inches. 



2-62 

 2-00 

 0-64 

 0-78 

 0-41 

 0-51 

 1-22 

 1-49 

 0-55 

 0-19 

 0-81 

 1-29 



R. badius. 

 9 



Inches. 



1-85 



1-50 

 0-48 

 0-64 

 033 

 0-43 

 1-03 

 1-14 

 0-40 

 0-20 

 0-66 

 0-94 



Ehizomys minor. Gray. Plates XV & XYI. 



RUzomys minor, Gray^ Ann. and Mag. Nat. Hist. 1842 vol. x., p. 266. 

 RUzomys minor, Horsfleld, Cat. Mamm. E. Ind. Co-^s Mus. 1851, p. 165. 

 Rhizomi/s minor, Schinz, Syn. Mamm. 1845 vol. ii., p. 126. 



