No. 446.] ORAL BREATHING VALVES OE TELEOSI\ 



free ed^e of the crescent 

 (Fig. 2, a), but may be 

 interrupted by a j^rojection 

 or a notch. (Fig. 2, r, d.) 



In the U-shaped ty])c, 

 the ends do not taper but 

 are bkmtly truncate. (Fig. 

 I, ;/.) The free margin in 

 these also may be perfect 



betore mentioned, the 

 edges a, c often nUeni 



•hed 



) the 



f the 



I he central thickening whu 

 )oth-like projection, may exten 

 r back between the 

 Mni-circular (in this 



ooth i)a( 



