PROFESSOR OWEN ON INDIAN CETACEA. 41 
of the condyle to the fore end of the symphysis. Each ramus has a convex, almost 
semicircular posterior margin, curving upward and backward from below (30), where the 
angle normally exists in other mammals, and then forward to the seat of the coronoid 
process (29): at the hindmost part of this curve the border is thickened to form the 
sessile condyle, adapted to the glenoid surface of the squamosal. Here the border bends 
outward: as the ramus advances, converging to its fellow, it is slightly bent with the 
convexity outward, which again is changed to a concavity (lengthwise), where it joins 
the opposite ramus to form the elongate symphysis (32), which is continued straight 
forward to its termination. The symphysis here forms rather less than a third of the 
entire length of the mandible, being 2 inches 4 lines in extent. The greatest vertical 
diameter of the ramus is 2 inches 2 lines; that at the beginning of the symphysis is 
8 lines!. In the alveolar groove are partially excavated sockets for nine teeth; the four 
middle intervals are severally equal to twice the basal diameter of the tooth: at the 
ends of the series, especially the anterior one, the alveolar intervals are less. The teeth 
(PL XII. fig. 1, and 4) are small, straight, conical, obtuse, not exceeding 8 lines in 
length, of which the cylindrical base has a diameter of 2 lines, that of the crown a 
diameter of 14 line, with a length of 24 lines, diminishing to a subrecurved apex. 
The loss of symmetry in this skull is hardly observable in the general contour, 
whether viewed from above (Pl. XIII. fig. 1) or below (fig. 2): it is chiefly, almost 
exclusively, confined to the nostrils and the bones concerned in the composition of those 
passages; and this is only conspicuous in the upper surface of the skull. 
In Euphysetes breviceps, Bl., according to the figure of the side view of the skull (copied 
in Pl. XTV. fig. 3), the occipital condyle is more prominent than in Euphysetes simus (P1. 
XII. fig. 1): the contour of the superoccipital is concave in Euphysetes breviceps, but is 
convex in Euphysetes simus—very feebly so, indeed, but as far as it departs from a straight 
line being in the direction of convexity. The most marked difference, however, is the 
greater proportional length of the rostral part of the, skull—measured, viz., from the ma- 
lomaxillary fissure (ib. & Pl. XIII. /) to the end of the upper jaw (22, ): in Huphysetes 
breviceps it forms about two-fifths of the entire length of the skull, in Ewphysetes simus 
about two-sevenths. The proportion of the maxillary, above the frontal and malar, on 
* «The condyle of the mandible projects from the posterior part of the ascending ramus, which is com- 
pressed and produced into a low obtuse coronoid process above, and into a similar angle below: a wide 
excavation, beginning at the inner side of the ascending ramus, deepens and contracts into the dental canal 
which enters the substance of the horizontal ramus: a fissure is continued along the inner side of the ramus 
from this canal, and is the sole indication of a compound structure of the jaw. The vessels and nerves emerge 
from several foramina at the outer side of the ramus, where it is attached by its long symphysis to its fellow: 
the upper border of the symphysial part of the ramus is excavated by a continuous dentigerous groove, some- 
what resembling, in the present foetal state, that in the upper jaw. The length of the symphysis in this 
skull is three-fourths that of the rest of the ramus. In the adult male the disproportionate growth of this 
part of the jaw leads to more excessive length of the symphysial part beyond the rest of the ramus.”— Op. 
cit. p. 444, foetal Physeter macrocephalus. 
VOL. VI—— PART I. G 
