226 THE ORIGIN OF VERTEBRATES 
= 
Fig. 97.—TRANSVERSE SECTION THROUGH THE OLFAcTORY PassaGE OF A YOUNG 
THELYPHONUS. 
1 and 2, sections of first and second appendages. 
we 
£6] 
Sui Dez 
SNE Miao 
a 
St 
ay: TES. 
rate: 
pa 
OO, 
Wel 
E 
" 
A! 
Scnorties socal 
Fic. 98.— TRANSVERSE SECTION THROUGH THE OLFACTORY PassaGE OF PETROMYZON. 
cart., nasal cartilage. 
