PROFESSOR OWEN ON INDIAN CETACEA. 37 
The vomer (Pl. XIII. figs. 1 & 2, 13, 13’) has partially coalesced with the presphenoid (ib. 
fig. 2,9) and underlaps the prefrontals (Pl. XIV. fig. 1, 14): it appears upon the palate, 
about an inch in advance of the posterior fissure (Pl. XIII. fig. 2, w), expands toa breadth 
of 6 lines (13), and is continued to the anterior end of the upper jaw, which it forms, 
contracting there to a breadth of 3 lines. Its under surface is flat; its upper surface 
(fig. 1, 13), which is similarly exposed on that aspect of the muzzle, is smoothly and 
widely canaliculate: the groove lodges the cartilage in the fissure separating the premaxil- 
laries (ib. 22), which cartilage terminates anteriorly the series of vertebral centrums, of 
which the vomer is the inferior or cortical ossification. The fore margin of the confluent 
prefrontals (ib. 14) isat 3 inches distance from the fore end of the vomer. The prefrontal, 
losmg breadth and gaining depth, recedes with a slight bend to the left, forming the 
inner boundary of the large left nostril (ib. 07) and the corresponding wall of the small 
right nostril (Pl. XIV. fig. 1, o/’). The nasal bones are confluent with that osseous mass 
(Pl. XII1.fig.1,15) which rises from the back of the septum narium and extends in a sinuous 
course, first convex to the left and then concave before subsiding at the vertex (15'): this 
ridge also sends off a kind of “spur” (15) from its right side, in the form of a short 
ridge, inclining to the right, with a convex border, thick and obtuse like that of the 
main ridge: the intervening space (ib. y) between these ridges expands as it extends 
forward, with a smooth sinuous surface concave across slightly contracting again as it 
ends behind the right nostril!. 
A trace of the suture of the palatines (Pl. XIII. fig. 2,20) shows that they entered into the 
formation of the bony palate for half an inch at the postpalatal end of the vomer ( 13‘), 
almost meeting each other behind that part: as they extend outward, they expand to a 
fore-and-aft breadth of 10’, with a convex surface, most so in their direction from 
within, outward and backward, contracting to terminate mesiad of the fossa (d): they 
develope no outer or free lamella in Euphysetes. 
a long superorbital process, the channel on the under part of which contracts, as it approaches the cranium, into 
a long, deep, and narrow groove. The median anterior part of the bone unites with both orbito- and ali- 
sphenoid, and external to this is the broad sutural surface for the sqnamosal. The straight median margins 
of the frontals are thinned off and joined by a squamous frontal suture, the right overlapping the left. The 
whole posterior and lateral border of the frontals, as far as the junction with the squamosal, presents a broad 
oblique sutural surface, which joins, by overlapping, the contiguous border of the occipital. The smooth 
cerebral surface of the frontal is flat at the middle, arched at the sides, and not impressed by any conyolutions.” 
—Physeter macrocephalus, op. cit. p. 442. 
1M. de Blainville figures, but makes no mention of this bony ridge bisecting the “postnarial” cavity. 
Dr. Gray, in appending the term Kogia to the Physeter breviceps, De Blainv. (Zoology of the Erebus and 
Terror, “ Cetacea,” 4to, 1846, p. 22), is equally silent—indeed, adds nothing to De Blainville’s meagre 
sketch of so remarkable a cranium, and quotes his admeasurements as in English inches and lines, without 
correction for the difference of the French “foot.” Macleay was the first who pointed out the heavy ridge 
of bone that longitudinally divides the spermacetic cavity into two unequal parts (op. cit. p. 47) as sub- 
generically distinguishing his Huphysetes from Physeter or Catodon. 
