PROF. W. K. PARKER ON A&GITHOGNATHOUS BIRDS. 501 
rostrum (pn), meeting beneath the axial parts; they are continuous with each other 
also; and this compound structure is one very important to be understood: morpho- 
logically the “recurrent trabecular cartilage ” (rc.c) is formed by the free ends of the 
cornua trabecule. 
The space between the front wings and their outer wall (a/. 7) is the external nostril 
(e. n). The outer wall of this nasal vestibule has in its inner side the large “alinasal 
turbinal ” (a. td); and this is separated by a narrow space from the subnasal (trabecular) 
lamine (77). 
Behind, both wall and turbinal are continuous with the bony vomer (v). All this is 
made clear by the transverse sections. 
The first of these (fig. 2) was made close behind the external nostril: the lateral 
and upper portions are here continuous. The razor has passed through the thick part 
of the nasal process of the premaxillaries (n.px), the upper crus of the nasal (7), the 
dentary part of the premaxillaries (d.px), the maxillary before it has given off the 
maxillo-palatine process (ma.p) and the prepalatine spur (pr.pa). Below, the nasal 
wall (n. w) rests in a groove of the maxillary; at its middle it gives off the “ alinasal 
turbinal” (a. td), which is large, and is thrice bent upon itself in an angular manner, 
giving off at the last two bends a slight secondary outgrowth. Above, the “ alinasal” 
passes into the “aliseptal” cartilage (al.s, fig. 3); and here we have a section of the 
fore end of its turbinal, the “inferior ”—anterior in the Bird, although below the others 
in Man. This is here scarcely more than half a cylinder. In this region the common 
wall between the nasal sacs is continuous with the crests growing from the flat, tilted, 
and coalesced ‘‘trabecule ;” these are seen to be large and curved. 
The next section (fig. 3) is through the maxillo-palatine processes (ma.p), which here 
are distinct in section from the marginal portion (ma); they form a pair of slanting 
planks, on which the compound vomer rests at its sides. The roof-bones (n, 1.pa’) are 
here flattened out over the broad gently swelling “aliseptal” roof. At this point the 
wall has died out below; and the aliseptal lamina, after growing downwards and inwards 
for a short distance, folds itselt suddenly inwards, and is coiled two and a half times 
(i. tb). Between these large inferior turbinals a differentiating cleft has appeared, 
causing a dehiscence of the nasal septum (s. m) from the trabecular bar and 
crest (tr). ‘The cartilages which lean towards this on each side are the common end 
of the alinasal wall and its turbinal; and the bony plate which is grafted upon both and 
binds them together is the vomer (v). The anterior face of the same somewhat solid 
section (fig. 4) shows more of the nasal cartilage; it is magnified twice as much. 
The part of the trabecular commissure and crest (f7) seen here shows it to be small; 
it is not, however, far from the “hinge;” the trough formed by the vomer and the 
“inturned alinasal lamine” (7. a. 7) is very deep and large; and in the adult the bony 
matter, creeping along the cartilage to some distance, gives the vomer, in the macerated 
skull, the appearance of one very deeply scooped bone. 
