422 Revieu's — W, Dames — On Archceopteryx. 



as it passes under the sclerotic ring, and does not extend so far as 

 the quadrate bone, it must be a part of the palatine-bone. The 

 quadrate bone may be easily known from its size, and also by its 

 articulation with the lower jaw ; there also appears to be an inner 

 flattened continuation, but it is not distinct enough to allow of 

 identification. Lastly, there is the little piece of bone which lies 

 in front of the quadrate bone, between the upper edge of the lower 

 jaw and the palatine. Its outline is an elongated oval ; it is arched 

 and smooth. From its length it belonged to the pterygoid. 



The Teeth. 



Even before the removal of the matrix that covered the front part 

 of the head, it was apparent that the ArchiBopteryx was furnished 

 with teeth ; one could see with a lens two small shining bodies under 

 the antorbital vacuity, as stated by Carl Vogt and also by Prof. 

 Marsh. In my notice of the head, I stated that a row of ten teeth 

 were seen, and that probably more might be found, which has subse- 

 quently proved to be correct. The teeth are seen to be continuous 

 quite to the extremity of the beak, and the matrix which covered 

 them having been carefully removed with fine needle-points, this 

 part of the skull is in the best state of preservation. The edge of 

 the jaw carrying the teeth is 16 mm. long, and extends from the 

 point of the beak to nearly the middle of the antorbital vacuity. 

 There are 12 teeth in the row, originally there were 13 ; but the last 

 tooth, which, from its position, was clearly visible, is broken off at 

 the edge of the jaw, and cannot now be seen. These 12 teeth are 

 almost of equal size and shape, measuring 1 mm. in length and 0*5 

 mm. in width; the upper part is cylindrical, and the lower half tapers 

 rather abruptly to a point, the sharp point ; bends rather under and 

 inwards. 



Their surfaces are polished and smooth, and show no ribs or furrows; 

 but when magnified, some minute vertical lines may be seen on the 

 anterior teeth, but they are not wider than cracks in the enamel. 

 The fifth and sixth teeth from the front are somewhat smaller than 

 the rest, and here the edge of the jaw bends forward, and the upper 

 part of the skull visibly projects, as if a little displaced ; so it is not 

 unlikely that here lies the boundary between the maxillary and the 

 intermaxillary bones. If this is the case, then six of the teeth are 

 inserted in the intermaxillary, and seven in the maxillary. Prof. 

 Marsh had expressed his opinion that the teeth stood in a groove, as 

 in Hesjjerornis. This idea I cannot share, but consider it certain that 

 the teeth are implanted in distinct alveoli. The alveoli have not been 

 actually' seen, but it seems impossible that a set of teeth, which 

 stood in separate places in the jaw, could have occupied one and the 

 same groove, as in Hesperornis. All the teeth are in their original 

 places standing perpendicular with their roots, fast in the edge of the 

 jaw ; all the teeth have clear interspaces between them ; they are 

 also in their original places with regard to one another. This 

 seems to me to prove satisfactorily that every tooth stands with its 

 roots in a sej)arate alveolus. 



