BIRDS WITH TEETn. 
347 
fig. 1 a), well illustrates this point ; and on referring to the skull 
(Plate CXXV., tig. 1 b) it will be seen that each serration on 
the beak of the Merganser has its corresponding denticle on the 
mandibular border of both the upper and lower jaws. Such an- 
other bird, with more powerful tooth-like serrations on its 
mandibles than are possessed by the Merganser, has lately been 
figured and described by Professor Owen from the London clay 
of the Isle of Sheppey, which has already yielded to the same 
distinguished comparative anatomist an ostrich, a vulture, a 
kingfisher, a small wading-bird, and numberless remains of 
Mammalia and Eeptilia of the greatest interest to the palaeon- 
tologist. 
This bird, the Odontopteryx toliapicuG of Owen, is repre- 
sented by a single skull,* which we reproduce on a reduced 
scale on Plate CXXV., fig. 2, has the bony denticles inclined at 
a considerable angle, their points being directed towards the 
anterior extremity, of the beak in both the upper and lower jaw, 
whereas in the Merganser they incline inwards towards the 
articulation of the jaws. In the fossil skull the tooth-like 
serrations vary, larger and longer teeth alternating at intervals 
with more numerous shorter ones. 
Professor Owen concludes “that Odontopteryx , like Archaeo- 
pteryx , was a warm-blooded feathered biped, with wings ; and, 
further, that it was web-footed and a fish-eater, and that in the 
catching of its slippery prey it was assisted by this pterosauroid 
armature of its jaws.”f 
Having thus, with the assistance of Professor Owen, disposed 
of the difficulty arising from the law of correlation, which 
requires that a beak and feathers should be associated together ; 
and having shown that both a fossil and a recent bird had un- 
doubted tooth-like serrations to their mandibles, let us next 
enquire whether the assumed possession of teeth coated with 
enamel and implanted in sockets (such as those which have been 
attributed to Archaeopteryx . See Plate CXXV., fig. 3 c.) by 
Mr. John Evans, are irreconcilable with the undoubted fact 
that it was an animal clothed in feathers. 
Eeferring to Professor Owen’s “ Comparative Anatomy and 
Physiology of Vertebrates,” 1866, vol. ii. chap. 17, p. 145, 
under the sub-heading “ Beaks of Birds,” is the following : — 
“ In place of teeth these bones are provided with a sheath of 
horny fibrous material, similar to that of which the claws are 
* The discovery of the ornithic character of this fossil, and the working 
out of the teeth, are due to my esteemed colleague in the Geological De- 
partment, Mr. William Davies, who has added so much to our knowledge 
of extinct life-forms among the Vertebrata. 
t “ Quart. Journ. Geol. Soc.” 1873, vol. xxix. p. 520. 
