622 THE OltGAN OF .TACOBSON IN MARSUPIALS, 



24. Symington, J. " On tlu^ homology of the dumb-bell-shaped 



bone in Ornithoi'hynchus." Journ. of 

 Anat. and Phys. 1896. 



25. ZucKERKANDL, E. " Das periphevische Geriichsorg. der Saug^- 



thiere." Stuttgart. 1887. 



REFERENCES TO PLATES. 



a.J.o., anterior prolongation of Jacobson's organ; a.ii., alinasal; gl., 

 gland ; J.c, Jacobson's cartilage ; J.o., Jacobson's organ ; I d., lachrymal 

 ducf. ; 3Ix., maxilla; «., nerve; n.f.c, nasal-Hoor cartilage; n.g.d., nasal 

 gland duct; n.p.c, naso-palatine canal; n.s., nasal septum; o.h.J.c, outer 

 bar of Jacobson's cartilage; o.ii.f.x., outer nasal-floor cartilage; jj.r., papillary 

 cartilage; Pmx., premaxilla; jxPmx., palatine process of preniaxilla; r.p., 

 ridge process of Jacobson's cai'tilage; r., vein; To., vomer. 



Pl.atk xm. 

 Dasyurus and PJtasrologcde. 



Figs. 1 - 4. — Transverse vertical section of Jacobson's organ and relations 

 in D. viverrinus (manj. feet., head length 15 nmi.), x 27. 



Figs. 5-9. — The same in D. ru'e>Tm((.s (two-thirds grown), x 12. 



Figs. 10-12. — The same in Phascolo(/(dfi jjcuicd/rtta (mam. foet., head length 

 9 mm.), X 36. 



Platk xlii. 



Did el ph }/■■<. 



Figs. 1 - 3. — Transverse section of region of Jacobson's organ in Didelphys 

 murina {iy\9.m. foct., head length 14 mm.), x 34. 



Figs. 4 - 8. — The same in D. marnupkdix (mam. fo?t., head length 37 mm.), 

 X 14. 



Fig. 9. — Transverse section of Jacobson's organ in D. marsupiatiK 



(mam. feet.), x 33. 



Plate xliii. 



Perameltx. 



Figs. 1 - 3.- — Transverse vertical section of region of Jacobson's organ in 

 Peranieles namta (mam. ioit., head length 21 mm.), x 30. 

 Figs. 4 - 7. — The same in P. vasida (two-thirds grown), x 17. 



