42 



CYC LOS TOM ATA 



tube is blind behind, but opens in front into the buccal cavity, 

 is nipped off from the oesophagus in post-larval life. 



It 



c > S 



the 



A v 



entr 



elum, probably homologous with that of Amphioxus, guards 

 ance into the pharynx in the hag-fishes, or into the branchial 



