DEVraOPMENT OF TEETH IN HATTEHIA PUNCTATA. 163 



Siebenrock (4) iu 1893 described a specimen having t\YO 

 vomerine teeth on the right side and one on the left. This 

 was the only instance of teeth occurring on the vomer out of 

 nine specimens examined. He states that the tips -were 

 covered with enamel. 



In the same year Rose (5) stated that he could find no 

 tooth replacement in Hatteria, although he apparently found 

 an " Efsatzleiste." He says "... trotzdem findet sich, 

 besonders im Oberkiefer, hinter den functiouirenden Ziihnen 

 eine wohl entwickelte Zalin- oder Ersatzleiste. Amhiateren 

 Eude derselben fiudet zeitlebens eine fortwahrende Neubil- 

 dung von Zahnen statt." It is, however, difficult to say from 

 the context whether he is referring to Hatteria, or Cham^leo, 

 or both. Latei', also, he says that in Chamseleo, '•' und ver- 

 mutlich auch bei Hatteria," there is behind the functional 

 teeth "eine gjin/lich f unctionlose^ abor wohl entwickelte 

 Zahn- oder Ersatzleiste.^' 



Burckhardt (6) in 1806, in a review of our knowledge of 

 the dentition of the Sauropsida, expresses his belief that the 

 form of the anterior teeth of Hatteria is due to concrescence. 



About the same time Baur (7) examined the skull of a 

 young Hatteria (25 mm. from premaxilla to occipital con- 

 dyle), and found two separate teeth in each premaxilla, an 

 outer larger and an inner smaller one, the latter having at 

 its base a replacing tooth, which, however, he says does not 

 become functional. In speaking of the maxilla also, he says, 

 "Der fiinfte Zahn besitzt wie der Innere des Premaxillare 

 eiiien Ersatzzahn, und der letzte steht frei in einer Alveole." 

 He found a well-developed tooth on each vomer, and in 

 addition an anterior small one on the left side. He states 

 that the second tooth in the mandible has an " Ersatzzahn," 

 and concludes that Hatteria has an incomplete set of succes- 

 sional teeth, which, however, are never functional. He does 

 not give his reasons for the latter part of his conclusion. 



Osawa (8), in 1897, stated that the teeth of Hatteria con- 

 sist chiefly of dentine. He could find no enamel, and to its 

 ' Tlie spacing is mine. — H. S. H, 



