PROFESSOR OWEN ON INDIAN CETACEA. 37 



The vomer (PI. XIII. figs. 1 & 2, i3, i3') has partiaUy coalesced with the presphenoid (ib. 

 fig. 2, 9) and underlaps the prefrontals (PI. XIV. fig. 1, u) : it appears upon the palate, 

 about an inch in advance of the posterior fissure (PI. XIII. fig. 2, w), expands to a breadth 

 of 6 lines (is'), 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 groo\'e lodges the cartilage in the fissure separatmg 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 

 prefi-ontals (ib. u) is at 3 inches distance from the fore end of the vomer. The prefrontal, 

 losing breadth and gaining depth, recedes with a slight bend to the left, formmg the 

 inner boundary of the large left nostril (ib. ol) and the corresponding wall of the small 

 right nostril (PI. XIV. fig. 1, ol'). The nasal bones are confluent with that osseous mass 

 (PI. XIII. 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 (is'): this 

 ridge also sends ofi" a kind of " spur" (is) 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 (is), 

 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 then- du-ection from 

 within, outward and backward, contracting to terminate mesiad of the fossa {d) : they 

 develope no outer or free lamella in Eujihysetes. 



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 squamosal. The straight median margins 

 of the frontals are thinned olf 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 convolutions." 

 — Physeter macrocephalus, op. cit. p. 442. 



' M. de BlainviUe figures, but makes no mention of this bony ridge bisecting the "postnarial" cavity. 

 Dr. Gray, in appending the term Kogia to the Physeter hreviceps, De Blainv. (Zoology of the Erebus and 

 Terror, " Cetacea," 4to. 1846, p. 22), is equally silent — indeed, adds nothing to De BlainviUe'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 spermacetie cavity into two unequal parts (pp. cit. p. 47) as sub- 

 generically distinguishing his Euphysetes from Physeter or Catodon, 



