In figure 26, the bifurcation at E is closer to the core than the bifurcation at D. However, E is not immediately in front of the divergence of the type lines and it _does not_ open toward the core. A--A and B--B are the only possible type lines in this sketch and it follows, therefore, that the bifurcation at D must be called the delta. The first ridge count would be ridge C. - _When there is a choice between a bifurcation and another type of delta, the bifurcation is selected._ A problem of this type is shown in figure 27. The dot, A, and the bifurcation are equally close to the divergence of the type lines, but the bifurcation is selected as the delta. The ridges marked "T" are the type lines. [Illustration: 27] [Illustration: 28] - _When there are two or more possible deltas which conform to the definition, the one nearest the core is chosen._ Prints are sometimes found wherein a single ridge enters the pattern area with two or more bifurcations opening toward the core. Figure 28 is an example of this. Ridge A enters the pattern area and bifurcates at points X and D. The bifurcation at D, which is the closer to the core, is the delta and conforms to the rule for deltas. A--A and B--B are the type lines. A bifurcation which does not conform to the definition should not be considered as a delta irrespective of its distance from the core. - _The delta may not be located in the middle of a ridge running between the type lines toward the core, but at the nearer end only._ The location of the delta in this case depends entirely upon the point of origin of the ridge running between the type lines toward the core. If the ridge is entirely within the pattern area, the delta is located at the end nearer the point of divergence of the type lines. Figure 29 is an example of this kind. [Illustration: 29] [Illustration: 30] If the ridge enters the pattern area from a point below the divergence of the type lines, however, the delta must be located at the end nearer the core. Ridge A in figure 30 is of this type. In figure 31, A--A and B--B are the type lines, with the dot as the delta. The bifurcations cannot be considered as they do not open toward the core. [Illustration: 31] [Illustration: 32] In figure 32, the dot cannot be the delta because line D cannot be considered as a type line. It does not run parallel to type line A--A at any point. The same reason prevents line E from being a type line. The end of ridge E is the only possible delta as it is a point on the ridge nearest to the center of divergence of the type lines. The other type line is, of course, B--B. The delta is the point from which to start in ridge counting. In the loop type pattern the ridges intervening between the delta and the core are counted. The core is the second of the two focal points.