  In our previous paper, we introduced a hyperbolic jigsaw construction and
constructed infinitely many non-commensurable, non-uniform, non-arithmetic
lattices of $\mathrm{PSL}(2, \mathbb{R})$ with cusp set $\mathbb{Q} \cup
\{\infty\}$ (called pseudomodular groups by Long and Reid), thus answering a
question posed by Long and Reid. In this paper, we continue with our study of
these jigsaw groups exploring questions of arithmeticity, pseudomodularity, and
also related pseudo-euclidean and continued fraction algorithms arising from
these groups. We also answer another question of Long and Reid by demonstrating
a recursive formula for the tessellation of the hyperbolic plane arising from
Weierstrass groups which generalizes the well-known "Farey addition" used to
generate the Farey tessellation.
