MOLGULA MANHATTENSIS 263 



6. Open the pharyngeal cavity by cutting through the wall of 

 the pharynx. Begin the cut below the liver, continue along the 

 endostyle and finish at the base of the cloacal siphon. Make a 

 drawing showing: endostyle; peripharyngeal groove; dorsal 

 lamina extending to the opening of the oesophagus; crown of 

 inner tentacles at base of the incurrent siphon; opening of phar- 

 ynx into oesophagus; pharyngeal ridges terminating in the 

 peripharyngeal ridge and converging toward the oesophageal 

 opening; volute-shaped adneural gland and, above it, the gan- 

 glion. 



7. With sharp scissors cut a specimen from which you have 

 removed the tunic, transversely a little way below the si- 

 phons. Make a drawing of the cut surface of the part with the 

 siphons, looking into the pharyngeal cavity. Label body wall; 

 pharynx; peripharyngeal cavity; pharyngeal ridges, peripharyn- 

 geal groove; vibratile tubercle; ganglion; endostyle; dorsal lami- 

 na; incurrent siphon with four branched tentacles of the first 

 order and eight of the second forming a sieve. 



Printed in the United States of America. 



