322 



but the left carries a suture disposed in an oblique manner so as to 

 produce a condition similar to that in the lion. Frassetto inclines 

 to the view that the condition can be explained by the assumption 

 that there are two supernumerary centres of ossification lying in front 

 of the more anterior of the two centres from which, according to the 

 contentions of Albrecht and others, the nasal is held to develope. 



The supernumerary nasal bones of the lion resemble, in a marked 

 manner, the Ossa inter nasalia as described by Mayer (13) and 

 considered by him as representing the Os rostri of various mammals. 

 The right bone — like the internasals of Man — is in contact with 

 the perpendicular plate of the ethmoid: but, unlike the human con- 

 dition, there is no indication of union between the right and left bones. 



It may be added in conclusion that in the same lion's skull there 

 is a small ossicle, on the right side, in the suture between the inter- 

 maxillary and superior maxillary bones on the margin of the alveolus 

 for the canine tooth (Fig. 2 2). On the left side, in the same position, 

 the suture is very irregular, and suggests that there was formerly a 

 similar separate ossicle here also. In another skull of a lion a few 

 months older than the one at present discussed, there is a disposition 

 of the suture which makes one suspect that an ossicle has been present, 

 but is now blended with the intermaxillary bone. It appears un- 

 reasonable to conclude that here is evidence of a "Mesognathion" of 

 Albrecht. It is more feasible to assume that we have to deal with 

 merely a sutural bone, the presence of which is doubtless to be as- 

 sociated with the large size of the canine tooth. 



References. 



1) Rosenmüller, Descr. partium ext. oculi. Leipzig 1797. 



2) Luschka, H., Das Nebenthränenbein. Müllers Archiv, 1858, p. 304. 



3) Budge, J., Das Nebenthränenbein Luschkas. Zeitschr. f. rat. Med., 

 1859, p. 278. 



4) Mayer, R., Das Nebenthränenbein. Müllers Archiv, 1860, p. 264. 



5) Macalister, a.. Notes on the Varieties and Morphology of the 

 Human Lachrymal Bone and its Accessory Ossicles. Proc. Roy. Soc. 

 Lond., Vol. 37, 1884, p. 229. 



6) Ranke, J., Die überzähligen Hautknochen des menschlichen Schädel- 

 daches. Abh. d. IL Kl. d. k. Akad. d. V^iss. München, Bd. 20, 1900. 



7) Zabel, E., Varietäten und vollständiges Fehlen des Thränenbeins 

 beim Menschen. Anat. Hefte, Bd. 15, 1900, p. 155. 



8) Grandidier et Filhol, Observations relatives aux Ossements d'Hip- 

 popotames. Ann. Sc. Nat., T. 16, Zoologie, 1894, p. 151. 



9) Cunninghaji, R. 0., On the Occurrence of a pair of Supernumerary 

 Bones in the Skull of a Lemur. Proc. Zool. Soc. Lond., 1896, p. 996. 



