| Garrod has observed that the chamber of the stomach which varies most among the Pecora is the psalterium. |
| Most, however, have four, the leaf stomach or psalterium being intercalated between the retinaculum and the abomasum. |
| The dorsal psalterium of the guinea pig was electrophysiologically studied with a view to possible commissural fiber groups and their properties. |
| The psalterium is reduced to a mere vestige, and so the stomach has, as in the Tragulina, but three chambers. |
