Oligochaetes sentence example
- The setae vary much in form and are often longer and stronger than in the Oligochaetes.
- 3) are among the most remarkable forms. Simple bifid setae, such as those of Oligochaetes, are also present in certain forms.
- In Polynoe the nephridia are short tubes with a slightly folded funnel whose lumen is intercellular, and this intercellular lumen is characteristic of the Polychaetes as contrasted with leeches and Oligochaetes.
- This differentiation is not, however, peculiar to the Polychaetes; for in several Oligochaetes the anterior nephridia are of large size, and opening as they do into the buccal cavity clearly play a different function to those which follow.
- In the Oligochaetes it is only the families Aeolosomatidae and Naididae that show the same phenomenon.Advertisement
- There is no communication between the nephridia on one side and the other, but in Eupolia there are ducts opening into the alimentary canal as well as to the exterior, a condition of things which recalls what obtains in certain Oligochaetes.
- Externally, the nephridium opens by a vesicle, as in many Oligochaetes whose lumen is intercellular.