Hornbostel - Sachs
End-blown conches
The air itself is the vibrator in the primary sense. The standing waves are significantly confined within the instrument itself. The air-stream passes through the player's vibrating lips, so gaining intermittent access to the air column which is to be made to vibrate. A conch shell serves as a trumpet. It is end-blown, and has no mouthpiece. India.
End-blown conches without mouthpiece