Anatomy of Notoryctes typhlops. 81 



relations greatly resemble those shown by Broom to exist in the 

 foetal calf.^ With reference to the transverse plates of cartilage 

 described by Broom as existing on each of the central rod, and 

 supporting the papilla between the naso-palatine canals, which is 

 so marked in Marsupials,^ such for example as in Didelphys 

 murina,'' in Perameles nasuta/ in Petaurus,'^ and Trichosurus,*^ 

 Phascolomys'' and Macropus.** I can find no trace of hyaline 

 cartilage in such a position, but the fibrous sheet of cartilage 

 which connects the main part of this prenasal between the 

 premaxillary processes with the nasal septum, sends out laterally 

 a thin ill-defined fibrous layer (Figs. 2 and 3, f.p.c), which 

 extends backwards beneath the palatal processes into the 

 papilla, behind which it does not exist. Apparently this 

 represents the papillary cartilage of other Marsupials, and that 

 of Miniopterus" and Macroscelides.^" 



Returning to the vertical transverse sections, we find that not 

 only the primary and secondary lateral ridges, but also the septal 

 cartilage are covered by a great thickness of glandular alveoli, 

 forming on the septum the superior septal ridge {s.s.r.). These 

 glands have well defined ducts, often. 06 mm. in diameter, running 

 longitudinally, to open far forwards into the vestibule. The 

 thickness of the glandular layer varies on the superior septal 

 ridge .24: to .52 mm., and on the superior lateral ridge .24 to .6 

 mm. The lining membrane of the nasal cavity over these i-idges 

 is smooth, like that of the Guinea-pig, and so unlike that of the 

 Rabbit, which is much plicated. About this vertical plane, the 

 cartilaginous projection, supporting the primary ridge from the 

 lateral wall, diminishes greatly in size and finally disappears, so 

 that on each side the cartilages of the nasal floor now form a 

 very shallow double U-shaped curve, each of the nasal furrows of 

 each side occupying the loop of one U, the mesial edge of the 



1 Proc. Linn. Soc. N.S.W., vol. x., n.s., pi. xliv., fig. 7, and p. 561. 



2 Loc. cit., fitf. 6, and p. 560. 



3 Proc. Linn. Soc. N.S.W., vol. xi., n.s., 1896, p. 597. 



4 Loc. cit., p. 599. 



5 Loe. cit., p. 604. 



6 Loc. cit., p. 607. 



7 Loc. cit., p. 613. 



8 Loc. cit., p. 610. 



9 Loc. cit., vol. X., n.s., 1895, pi. xliv., figs. 4, 5, p. 560. 



10 Proc. Zool. Soc. Lond., 1902, vol. i., pi. xxi., figs. 8, 10, p. 226. 



