108 Proceedings of the Royal Society of Victoria. 



Eefebence Letters (Continued). 



Sciatic artery. 



Superficial femoral artery. 



Secondary lateral ridge. 



Sviperior septal ridge. 



Superior vesical artery. 



Ureter. 



Vein. 



Vas deferens 



Ventral nasal furrow. 



(A// Figure<: tvere drazini by the aid of the Camera Lucida). 



Figure 1. 



Transverse vertical section through the anterior portion of the 

 head of Notoryctes shov^ing arrangement of cartilages forming 

 nasal septum {n.s.c), alinasals (a.c), ventral processes from the 

 septum (n./.c), and the prenasal cartilage {/>.c.) ; also the 

 premaxillary {/>.d.) and nasal {/i.b.) bones. The naso-lachrymal 

 duct (n./.d.) is seen pa.ssing through its canal immediately 

 posterior to the union of the alinasals and the cartilages of the 

 nasal floor {n.J.c), to open into the ventral nasal furrow 

 anteriorly. Zeiss A,* oc. 2. 



Figure 2. 



Ventral median portion of trsnsverse vertical section through 

 head, a considerable distance behind Fig. 5, and just in front of 

 Jacobson's Organ, to show swelling in Jacobson's cartilage (_/.^.) 

 which has, on the right side, quite lost its anterior connection 

 with the nasal septum (n.s.c), and on the left is just losing it. 

 The naso-lachrymal duct is seen {n.l.d.) to lie in its groove in the 

 alveolar process of the bone outside the outer nasal floor carti- 

 lages {n.J.c). The ill-defined papillary cartilage {f.p.c.) is seen 

 ventral to the palatine processes of the premaxillary bone {p.p. p.). 

 Zeiss A,* oc. 4. 



Figure 3. 



Complied from two consecutive transverse vertical sections 

 through Jacob.son's Organ {/.O.) at the point where its duct 



