Here we describe a new Photinina genus with three species endemic to Serra dos Órgãos Mountains in Brazil. Ybytyramoan gen. nov. occurs in high altitudes, from 980m up to 2000m, and has the following unique set of characters: head abruptly depressed at vertex; lanterns not fully developed, somewhat rounded or anteriorly rounded, straight posteriad, with posterolateral rounded projections (billy...

We produce an explicit parameterization of well-rounded sublattices of the hexagonal lattice in the plane, splitting them into similarity classes. We use this parameterization to study the number, the greatest minimal norm, and the highest signal-to-noise ratio of well-rounded sublattices of the hexagonal lattice of a fixed index. This investigation parallels earlier work by Bernstein, Sloane, ...