Not a west flowing river: Tamraparni

Explanation:
- West flowing rivers in India refer to the rivers that flow from east to west, emptying into the Arabian Sea.
- Periyar, Bharatpuzha, and Pamba are all examples of west flowing rivers in India.
- However, Tamraparni is not a west flowing river.

Tamraparni River:
- Tamraparni River is located in the southern part of India, primarily in the state of Tamil Nadu.
- It is a perennial river that originates from the Agastyarkoodam peak in the Western Ghats.
- The river flows in a generally eastward direction and empties into the Gulf of Mannar, which is a part of the Bay of Bengal.
- Therefore, it is not a west flowing river.

Importance of Tamraparni River:
- The Tamraparni River holds significant historical and cultural importance.
- It is mentioned in ancient Tamil literature, including the Sangam literature.
- According to legends, the river is associated with ancient kingdoms and is believed to have been a significant trade route in ancient times.
- The river is also considered holy and is associated with various religious traditions.

Conclusion:
- Among the given options, Tamraparni is the river that does not flow westward.
- It flows in an eastward direction and empties into the Bay of Bengal, making it different from the other three west flowing rivers mentioned.