- Cam, The camerostome or upper lip. M, The mouth.
- Obi, Camerostome (upper lip).
- On the 1 A pair of round tubercles on the labrum (camerostome or hypostoma) of several species of Trilobites has been described and held to be a pair of eyes (22).
- In the latter the single pair of antennae springing up from each side of the camerostome or hypostome or upper lip-lobe are seen.
- A, Camerostome or epistoma.