SKULL AND OTHER BONES OF LOXOMMA ALLMANNI. 205 



depression, which varies in size with the distance at which the 

 teeth are apart. These depressions, it has been said, are des- 

 tined for the reception of the points of the mandibular teeth when 

 the mouth is closed ; as, however, we doubted the correctness of 

 the assertion, Mr. Atthey made transverse sections through these 

 depressed spaces and the adjacent parts of the jaw, taking in 

 some of the teeth ; and then, under a low magnifying-power, we 

 discovered in each case, a little below the surface of the depres- 

 sion, the remains of the root of a former tooth. Depressions of 

 the same character existing along the alveolar border of the 

 maxillae were next, in several instances, similarly examined in 

 section, and with the same result ; the remains of a tooth existed 

 in each. These depressions, therefore, instead of lodging the 

 teeth of the other jaw during closure of the mouth, are the ves- 

 tiges of former alveoli from which old teeth have been shed. 

 Besides, it can be shown that the teeth of the mandible are not 

 received into- these depressions when the mouth is closed ; for 

 the upper jaw, forming the larger arch, must, when the mouth 

 is shut, enclose the corresponding part of the mandible ; more- 

 over the teeth of the mandible, when the mouth is closed, do not 

 otherwise correspond to the depressions of the maxilla. 



The median suture between the premaxillaries is distinct, and 

 is thence continued backward, first between the vomerine palate- 

 plates and then between those of the palate-bones and the ptery- 

 goids as far as the posterior border of these last. 



At the posterior border of the premaxillaries this suture is 

 crossed by a transverse one, uniting these bones with the vomer- 

 ine plates. The latter suture is projected forwards on the median 

 line by a rounded prominence of the vomers ; from this on each 

 side it curves forward and outward and then backward, thus 

 surrounding a considerable part of the base of the vomerine tusk, 

 from which it is distant only by about an eighth of an inch. It 

 terminates at the borders of the jaw, uniting at that part the 

 contiguous ends of the premaxillaries and of the alveolar borders 

 of the maxillaries. 



The vomers, immediately behind the premaxillaries, stretch 

 almost entirely across the palate, and are separated from the 



