560 PROF. OWEN ON THE ENDOTHIODONT REPTILIA. 
tribute to form the roof of a large, deep, and smooth depression 
(ib. 22’) at the fore part of the palate. This depression is bounded 
laterally by the caniniform processes and anteriorly by the deflected 
fore end of the beak-shaped premaxillary. It has not the pair of 
longitudinal ridges at the fore part as in Dicyncodon (op. cit. p. 46, 
pl. xxxix. 22/, pl. xliv. fig. 2, 22*), and in this respect resembles 
Oudenodon (op. cit. pl. lvi. fig. 2, 22); but Hndothiodon uniseries, like 
E. bathystoma, repeats the same palatal character as in both those 
Anomodonts, in the vault-like expanse of the fore part of the roof 
of the mouth f. 
From the hind part of the concavity the confluent premaxillaries 
are continued backward as a narrow process, convex lengthwise 
and across, perforated by a premaxillary slit (ib. ib. ap) and ter- 
minating pointedly between the parial yomerine plates (1b. 13, 13). 
The nostrils (figs. 2 & 5, n n) are divided anteriorly by the 
deflected fore part of their roof, the fore end of which is broken off, 
showing the thickness of the nasal septum at that part (Pl. XXVII. 
fig.5,ns). Each nostril has a trilobed shape ; the fore lobe is defined 
from the hind one by the deflected fore part of an antero-posteriorly 
extended large and massive nasal bone (figs. 2, 4, 5,15). The third 
smaller and lower lobe of the nostril extends between the premax- 
illary (fig. 2, 22*) and maxillary (ib. 21*) into the base of the ca- 
niniform process. The antero-posterior extent of the nostril is 
1 inch 6 lines, the vertical diameter is 8 lines. It markedly differs 
in shape, and independently of distortion, from that of the nostril 
of Endothiodon bathystoma (op. cit. pl. lxvi., 2), in which, however, 
the same extension of the cavity into the premaxillo-maxillary cleft 
at the base of the caniniform process is shown. The suture between 
the maxillary (21) and the nasal (15) has the same course in Endothi- 
odon unisertes as in Hndothiodon bathystoma. 
The resemblance of the outer nostril to that in Oudenodon magnus 
(op. cit. pl. liv.) may be noted, in which a hinder lobe or division 
of that orifice is indicated by a prominence of the upper border, due 
apparently to a similar forward extension and descent of the nasal 
bone. The lower border of the nostril is also notched where it is 
continued into the premaxillo-maxillary suture (see also Oudenodon 
Bain, op. cit. pl. lx. fig. 1, 2); but this is more in advance of the 
caniniform process in Oudenodon than in EKndothiodon. 
The nasals (15) are separated from each other, as in most Birds, 
by the backward extension to the frontals (11) of a long and strong 
nasal or facial production of the premaxillary (fig. 4, 02). The trans- 
verse convexity and longitudinal deflection of this part of the pre- 
maxillary is as well marked in the smaller as in the larger species, 
and recalled the proportions of the same bone in Aptornis otidi- 
forms t. 
t The roof of the corresponding palatal concavity in Dinornis robustus shows 
a single median ridge (‘Iixtinct Birds of New Zealand,’ 4to, vol. ii. pl, Ixy. 
fig. 1, 22). 
t Memoirs on the Extinct Wingless Birds of New Zealand, 4to, yol. ii. 
pl. xliii. figs. 1 and 2, 
