OSTEOLOGY AND DENTITION OF HTLOMTS. 461 



cally extended tooth of the whole lower jaw. The crown is long, conical; and slightly 

 recurved ; and the cingulum encircling it forms a process anteriorly and posteriorly at 

 its base, but no distinct cusp. The first and second molars have five cusps, of the same 

 form and arrangement as in Erinaceus, with the cingulum very strongly marked 

 externally. The third molar, which is only a little more than half the size of the first, 

 has also five cusps, the anterior of which, however, is even less developed than it is in 

 the second molar. 



The basihyal is a fiat, transversely extended, bony plate, consisting of two halves 

 placed side by side, with a posterior comu directed outwards and backwards, to which 

 the slender, slightly upwardly curved thyrohyal is attached. The ceratohyal is a short, 

 rather stout, cylindrical bone, constricted in the middle, with a head at either end ; and 

 it is succeeded by another, slender, laterally compressed bone, bent at its upper half — 

 which leads me to believe that it is the stylohyal. But as the hyoid apparatus before 

 me is imperfect, I cannot speak with any degree of confidence as to the number of 

 pieces in the anterior arch. 



Measurements of the Skull of Hylomys peguensis, Blyth. 



in. lin. in. lin. 

 Greatest length of skull to tip of intermaxUlaries . . . . 1 4^ to 1 4f 

 Greatest breadth across zygomatic arch 9 „ 8f 



Greatest breadth of squamosal 7 „ 65 



Breadth above lachrymal process 5| „ 5§^ 



Lachrymal process (upper margin) to tip of intermaxillaries .0 7 „ 7^ 



Breadth in front of canines 2f „ 2| 



Breadth in front of fourth premolar . . . .. . . .0 4 „0 4 



o 



Breadth (external) at first incisors 2 „ 



Breadth behind supraorbital process 4 „ 3f 



Least breadth between orbits 4| „ 4^ 



Posterior palatine margin to tip of intermaxillaries . . . 9 „ 8f 

 Greatest breadth between alveolar internal margins (between 



second and third molars) .S|^ „ 3 



Length of alveolar border 9 „ 8^ 



Breadth behind origin of zygomatic arch, inferior aspect of 



skull 7 „ 6i 



Distance between tympanic bullae (anterior extremity) . , 1 „ 1 



Distance between tympanic bullse (posterior extremity) . .0 4§ „ 4| 



Depth of skull at anterior extremity of nasals If „ 1| 



Depth of skull at posterior extremity of nasals 3 ,,0 2^ 



Depth through posterior margin of palate 4f „ 4^ 



Depth through highest point of parietal 4| „ 4| 



VOL. VIII. — PAB.T VIII. April, 1874. 3 t 



