Aristotle's lantern which helps in mastication is a characteristic feature of
1)Asterian (Star fish)
2) Echinus (Sea urchin)
3) Antedon (sea lily)
4) Ophiura (brittle star)

Options

A. Asterian (Star fish)
B. Echinus (Sea urchin)
C. Antedon (sea lily)
D. Ophiura (brittle star)

Explanation

**Step-by-Step Solution:**

1. **Understanding Aristotle's Lantern**:
- Aristotle's Lantern is a specialized structure found in certain marine organisms. It is a complex arrangement that includes muscles, calcareous teeth, and plates.
- This structure functions as an eversible organ, primarily aiding in the process of mastication, which is the act of chewing food.

2. **Identifying the Function**:
- The primary function of Aristotle's Lantern is to help scrape algae and other food from rocks, allowing the organism to effectively consume its food.

3. **Classifying the Organisms**:
- The question provides four options: Asterian (Starfish), Echinus (Sea Urchin), Antedon (Sea Lily), and Ophiura (Brittle Star).
- Among these, we need to identify which organism possesses Aristotle's Lantern.

4. **Analyzing the Options**:
- **Asterian (Starfish)**: Starfish do not have Aristotle's Lantern.
- **Echinus (Sea Urchin)**: Sea urchins are known to possess Aristotle's Lantern, which they use for mastication.
- **Antedon (Sea Lily)**: Sea lilies do not have this structure.
- **Ophiura (Brittle Star)**: Brittle stars also do not possess Aristotle's Lantern.

5. **Conclusion**:
- Based on the analysis, the correct answer is **Echinus (Sea Urchin)**, as it is the organism that has Aristotle's Lantern for mastication.

**Final Answer**: Echinus (Sea Urchin)

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