160 MR. W. K. PAEKEE ON THE STEUCTUEE AND 



the nasal is a small style, which lies obliquely in front of the exposed upper part of the 

 lacrymal ; it does not reach the gooseberry-prickle-shaped ascending process of the pre- 

 vomer (Plate XIV. fig. 1,^.«.). The posterior nasal blades are scooped; the thick part 

 has large pores ; the anterior narrower part is strongly convex, each bone fitting itself 

 on to its own primordial mould or pattern, e. g. the arched wings that give off the rich 

 inferior turbinal outgrowth. Although the nasal be a mere splint — an " aliseptal oper- 

 culum " — yet its development and modification are of great interest to the morphologist. 

 I shall therefore, in this case, anticipate my future papers, and compare this part of the 

 Cassowary's head with that of another of the " Grallse," indeed, but with one which 

 ranks above most of that heterogeneous " Order," viz. with the " Aves Altrices." The 

 common Heron (Ardea cinerea) shows to what typical height a wading bird may attain, 

 and I am fortunate in possessing the skull of a fledgling*. 



The whole length of this skull is 5 inches 9 lines, and yet the intermaxillaries, 

 measured along the nasal processes, are 4 inches 2 lines in length ; the solid part is 

 9^ lines in extent, and the dentary margin, to the end of the angle, 2 inches 10 lines. 

 The entire length of the nasals is 3|^ inches ; their hinder part is broad, flat, splintery, 

 and pointed at the extreme end ; at the broadest part they meet within half a line ; but 

 the very delicate styloid ends of the intermaxillaries can be seen between them, lying 

 on an acutely-angular space between the frontals, and showing a trace of the ethmoid. 



The nasals in front of the lacrymals divide, the upper crus, wholly separated from 

 its fellow, becoming gradually an extremely delicate style, which runs up to the solid 

 part of the intermaxillary. The lower crus of the nasal is thick, descends obliquely 

 forwards, lies on the prevomer, and has the flat fibrous angle of the intermaxillary 

 clamping its outside. The suture between the nasal processes of the intermaxillaries 

 can be traced nearly forwards to the solid part of the bone, viz. for 3 inches 3 lines. 

 The prevomers reach within an inch of the end of the beak in front, and within 4 lines 

 of the quadrate bone behind; they are 3 inches 8 lines in fore-and-aft extent; the 

 whole extent of the intermaxillary apparatus being 4 inches 9 lines, one inch less than 

 the length of the whole skull and face. This disproportion of the intermaxillary appa- 

 ratus becomes still more inordinate in the adult bird, and much more extraordinary 

 measurements could be given from the skulls of the "Ibidinse" and "Tringinse." 



The nasal processes of the intermaxillaries (Plate XIV. figs. 1 & 3, px.) in this 

 young Mooruk are less than half an inch long, one-seventh the length of those of the 

 young Heron, a bird not much more advanced in development, and of a smaller size. 

 In the Ouaran Lizard (Psammosaurus scincus), a species of Monitor, the single process 

 of the azygous intermaxillary cleaves the azygous nasal ; this styliform compressed 

 process is longer than its counterpart in the young Mooruk. Amongst the mammals 

 the "Leporidse" have the largest intermaxillaries (if we except the Cetacea, Mono- 

 tremata, &c.) ; but the long process which each bone gives off, to pass upwards and be 



* This bird, although ready to fly, had not left its elevated cradle ; it was from the heronry in Milton Park, 

 Northamptonshire, on the estate of Earl Eitzwilliam. 



