386 MAMMALIAN ANATOMY 



been also employed, and is found translated into the German das 

 Muschelbein, or untere Muschel. The French use le cornet inferieur. 



Determination. When the bone is held with the scroll-bearing 

 medial side toward the student and the larger scroll downward, the 

 pointed posterior end will be on the side to which the bone belongs. 



Articulation. The maxillo-turbinal articulates directly only with 

 the maxillary ; in some specimens it touches the lachrymal and the 

 lateral ethmoid. 



Ossification. The maxillo-turbinal is developed from a single 

 centre of ossification. 



HUMAN MAXILLO-TURBINAL BONES. 



The human maxillo-turbinal, often known as the inferior tur- 

 binated bone, is more simple than the corresponding bone of the cat, 

 in that it consists of a single scroll. 



It presents a convex inner surface (Fig. 307) and a concave outer 

 surface (Fig. 308) ; both extremities are pointed, the posterior more 

 acutely. 



FIG. 307. 



THE RIGHT NASAL CAVITY, OUTER WALL. 



], frontal bone ; 2, its orbital plate ; 3, its nasal spine ; 4, nasal bone ; 5, ethmoid bone ; 6, superior turbinal ; 

 7, middle turbinal; 8, maxillo-turbinal bone; 9, descending process of the lachrymal bone, within the position 

 of which is the nasal duct; 10, nasal spine of the maxillary; 11, naso-palatine canal; 12, palatine plate of the 

 maxillary; 13, nasal process of the latter; 14, external pterygoid plate; 15, internal pterygoid plate; 16, nasal 

 plate of the palatine bone ; 17, its palatine plate ; 18, posterior palatine foramen ; 19, superior meatus of the nose ; 

 20, middle meatus; 21, inferior meatus; 22, frontal sinus; 23, sphenoidal sinus; 24, its communication with the 

 upper back part of the nasal cavity ; 25, spheno-palatine foramen ; 26, orifice of the antrum. 



The superior border gives off in front and above a lachrymal 

 process, which articulates with a process of the lachrymal bone. 

 Behind this process is an ethmoidal process, which projects upward 



