Theinred of Dover (mid-12th century) proposed a new species theory accommodating chants requiring more chromatic tones than those available in the Guidonian gamut. Theinred presents his species first in tables; species of many intervals are also illustrated in circular and spiriform diagrams. The figures of concentric circles are organized with the spokes marking steps; individual species ascend clockwise. In the spiriform diagrams, the spirals mark steps; individual species ascend along the spokes from near center outward. To conclude his discussion, he presents series of conjunct diapentes and diatessarons, in a proportionally spaced table, resulting in Daseian and “anti-Daseian” scales, which can also be imagined as a pair of helices.