Fig. 9 Cross section through the anterior part of the orbital region of the same 

 embryo, showing the septum interorbitale (s.i.) and the posterior part of the olfac- 

 tory capsule, the planum antorbitale (p. ant.) and the cartilago ectochoanalis 

 (c.e.) alone being cut. ^ 15. 



Fig. 10 Cross section through the posterior part of the ethmoidal region of the 

 same embryo showing the lack of continuity between the olfactory capsule pos- 

 teriorly and the septum interorbitale. X 15. 



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