CHORD AT A 



425 



Sub-class I. Enteropneusta. 



Chaeacteeistics. — Soft worm-like animals with ciliated ectoderm. 

 The trunk, succeeding the collar, is long and somewhat 

 flattened. The alimentary canal is straight, and the anus 

 opens at the end of the trunk. There are numerous gill- 

 slits, which increase in number during life. 

 There are several species of Balanoglossus described. 



Fig. 244. — View of an adult male Balanoglossus Kowaleoskii. Magnified one and a 

 half times. After Bateson. 



1. Proboscis. 



2. Collar, 



3. Trunk. 



4. Begion of Testes. 



5. Tail. 



6. Mouth. 



7. Gill-slits. 



8. Lateral edge of the body where it 



becomes flattened, 



9. Anus. 



B. clavigerus and minwtus are found in the Bay of Naples, 

 B. salmoneus and roiinii off the coast of Brittany. The 



