MR. W. K. PARKER ON THE OSTEOLOGY OF BALENICEPS REX. 297 
grooves, and again thickens so much towards the rather sharp margin as to give it the 
appearance of curving in. 
In the Boat-bill all these characters are softened and feeble: the mesial portion is, as 
it were, pinched into a keel, convex along the mid-line and concave at its sides ; whilst 
the grooves are wider and more open, and the sides of the jaw smooth and evenly 
convex as they turn slightly inwards to form the sharp margin. The great upper 
grooves are nearly obsolete in the Adjutant; in the Heron they are well marked 
in front of the nasal fosse, but only pass halfway to the straight tip. In the Pelican 
they are distinct for two inches from the nasal fossz, when they lose themselves in the 
large cellular scoopings that occupy so much of the interspace between the moderately 
convex ridge and the margin; yet the upper margins are indicated all the way by a 
row, on each side, of large oval vascular apertures, and again become distinct as they 
form the boundaries of the beaked tip of the bill. In the Spoenbill these upper pre- 
maxillary grooves are very distinct: diverging as they pass out from each nasal fossa, 
they run within one-tenth of an inch of the margin in the narrow part, and one-eighth 
in the broad spatulate end, round which they pass to become confluent above, a little 
posterior to the broad and gently curved tip. The large concave ‘hard palate’ of the 
Baleniceps is not a whit less elegant than the upper and lateral aspects of the jaw— 
indeed more so, if possible ; the vascular grooves being here very perfect, as they pass 
out at right angles to the great mesial sinus, forking and inosculating laterally like the 
veins of a beautiful leaf. 
To the distance of 1} inch from the tip, the mesial line below is keeled, at first rather 
sharply, but the ridge soon becomes convex, and widening as it passes backwards, is 
in reality continued along the greater part of the palate; but at the distance above- 
mentioned it is laid open—no longer a ridge, but a large vascular sinus. 
For more than the anterior half this groove is sharply margined, and, besides the 
vascular openings into the lateral dendritic grooves, exhibits large open spaces which 
communicate with the rich diploé occupying the thick mesial ridge of the jaw. The 
margins then become smoother and more rounded, and the groove wideus as it passes 
backwards to descend rather suddenly to the posterior boundary of the hard palate. 
Turbinals or Ethmoidal Pterapophyses'. (Pl. LXV. fig. 7, tb.) 
From the inner part of the articulation of the palatine with the pre-maxillary there is, 
on each side, a smooth convex ridge, which runs forwards for above an inch, slightly 
converging towards its fellow. A little behind where these ridges lose themselves in 
the surrounding bone there is an irregular opening about two lines in length, which opens 
from the mesial groove obliquely into the space above. Behind this there are several 
smaller passages scarcely true to the mid-line. These openings are all of them the 
remains of a membranous space, which is large in many birds, and lies in front of and 
1 We have adopted this term provisionally ; Professor Gcodsir would haye us believe that these elements are 
neurapophyses (see op. cit. p. 144). 
