OSTEOLOGY AND DENTITION OF HYLOMYS. 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 EHrinaceus, 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 flat, transversely extended, bony plate, consisting of two halves 
placed side by side, with a posterior cornu 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. Ha. an:) hn. 
Greatest length of skull to tip of intermaxillaries . .1 4¢$tol 43 
Greatest breadth across zygomatic arch ORs De cO ss 
Greatest breadth of squamosal Oe fox £1 Onn62 
Breadth above lachrymal process O- 5Z ,,,. 00 oF 
Lachrymal process (upper margin) to tip of srlietrnsent tice Oleh Ole ie 
Breadth in front of canines 5 One22 +022 
Breadth in front of fourth victnie .0 4 ,0 4 
Breadth (external) at first incisors . OZ Owe 
Breadth behind supraorbital process wiOqgetea5. 0b 134 
Least breadth between orbits . nO) dee O ait 
Posterior palatine margin to tip of ‘affieronillorie’ oF On Orne 08 483 
Greatest breadth between alveolar internal margins ( between 
second and third molars) Oi az°;, 08 
Length of alveolar border . : Dae Doers, One 
Breadth behind origin of zygomatic sail, inferiot ‘apart of 
skull . eat Ont nOo6z 
Distance between Soin bulls: feast sake it) Opal sere Ooh 
Distance between tympanic bulle (posterior extremity) 0 42,,0 43 
Depth of skull at anterior extremity of nasals . 0 12, 0 14 
Depth of skull at posterior extremity of nasals . 0 3 , 0 24 
Depth through posterior margin of palate 0 42,0 42 
Depth through highest point of parietal . 0 48,,0 42 
VOL. VIII.—PART vill. April, 1874. 3T 
