This is the second surface of this type that exhibits Costa nodes in the limit. There are also interesting diagonal tunnels in a 45 degree view. The divisor of the squared Gauss map is below.

Below are 8 copies of a translational fundamental piece near the two limits: The left limit consists of three genus 0 Scherk and a genus 1 Karcher-Scherk surface, the right planes joined bu Costa and catenoidal necks. Compared to type I-A-3, the relative position of the necks is different.

##### Resources

Mathematica Notebook

PoVRay Sources