28 PEOFESSOR OWEN OX INDIAN CETACEA. 



anterior ends, giving place to the premaxillaries ( 22' ), which forai the apex of the 

 muzzle : the rest of the disposition of the maxillaries accords with Cuvier's account in 

 Phoccena (jlohiceps; the superorbital plate (fig. 1, 21* ) is divided by a notch from the 

 lostral part ( 21 ) of the maxillary, and forms a tuberosity articulated with the under- 

 lying malar ( 26' ). The premaxillaries ( 22 ) accord equally with those in P. glohiceps, 

 save in their shorter proportions concomitantly \vith the shorter muzzle. They are 

 perforated near the outer margin, between the posterior and middle third, the canal 

 leading forward and inward. The three perforations (fig. 2, a, h, c) in the maxillaiy 

 external to the nasal portions of the premaxillary ( 22'), are the upper outlets of canals 

 which converge to open into an oblong fossa (fig. 3, 26) beneath the fore part of the roof 

 of the orbit. 



The pterygoid (fig. .3, 24, 24' ) is a large sinuous plate folded upon itself from within, 

 upward, outward, and backward ; the thick fore part (24) articulates with the palatine, 

 whence it continues the bony roof of the mouth backward for the extent of 1" 8'", 

 with a convex surface, divided from its fellow by a vacancy of 8'" breadth, exposing the 

 presphenoid and vomer ; the inner plate of the pterygoid forms the outer wall of the 

 lower part of the nasal passage, and continues that passage obliquely backward, as an 

 open canal (24'), beneath the base of the alisphenoid (6), as far as the otocranial 

 plate of the basisphenoid (s' ). This posterior production of the pterygoid is three-sided ; 

 the inner or narial one is concave ; the outer one is also concave, forming a channel 

 leading upward and forward to the orbit ; the upper facet is sutural, and articulated 

 with the basi-, pre-, ali-, and orbito-sphenoids. The anterior external lamina of the ptery- 

 goid bends outward and upward to articulate with the corresponding free lamina of the 

 palatine, bounding the narrow and deep sinuous fissure between the outer and inner 

 portions of both bones. 



The malar, as in other BelpMnidcc, consists of the antorbital (PI. IX. fig. 1, 26' ) and 

 styliform (26) portions. The former ( 26' ) is a narrow triangle, with the base thick, convex, 

 turned forward, underpropping the fore part of the superorbital plate of the maxillary 

 ( 21* ), and articulating with the same part of the frontal ; the apex extends backward, 

 and is wedged into the roof of the orbit between the frontal and maxillary. The 

 styliform portion (26) is given off by a process extending inward (mesiad), at right 

 angles to the antorbital portion (fig. 3), and a few lines behind its fore part; it sud- 

 denly contracts and extends backward, with a slight bend, to the squamosal, articu- 

 lating by a concave, oblique, terminal facet to a tubercle at the fore and under part 

 of the zygomatic process of the squamosal (fig. ] , 27). The length of this part of the 

 malar is 3" ; its thickness throughout the greater extent is 1|"' by 1'" ; its squamosal 

 articulation is 4" across. The form of the orbit (ib. or) so defined below is longitu- 

 dinally oblong, more arched above than below, 2" 2'" in fore-and-aft diameter, 1" 2'" 

 in greatest vertical diameter ; the chamber communicates, of course, largely with the 

 temporal fossa, and continues into the deep, ascending orbital fossa and the small 

 antorbital fossa (r/), external to which is the rough malomaxillary fossa {e). 



