The Atlas-monograph presents a novel approach to the study of the development of snow cover based on its crystal morphology and the fundamental laws of natural symmetry. The Atlas displays more than 320 microphotos of crystals of depth hoar and newly fallen, wind-transported, and small- and medium-grained snow in various mountain and flatland regions of Russia. The principal types of geometrical symmetry are shown along with the phase forms of crystal growth and decomposition and constructive and regressive metamorphism in both loose and dense snow. Illustrated are the morphological features of contact interaction between particles in crystal aggregates under free and tightly packed conditions of growth. Phototables of crystals are furnished with schematics and essential explanatory comments underscoring the most important crystal-morphological features of the hydrothermal fields and the fields of deforming stresses in the snowpack. The presented conceptual model describes the unclosed sublimation-metamorphic evolution cycle of seasonal snow cover and the regional variants of this cycle as its polymorphic (in that number regional) modifications. This model serves as a cornerstone of evolutionary concept. Snow cover is represented as a natural community of the shapes of growing crystals interacting with each other and exposed to environmental influences. It is worked out of the empirical deterministic models describing the sublimation-metamorphic cycle of seasonal snow cover and the polymorphic variants of this cycle. The main driving force of processes yielding an evolutionary row of crystals is the internal interactions within a snow pack. For all that the factor of time (the age of the genetic player) plays a crucial role in sublimation metamorphism. Stadiality of the forms of crystal growth and self-development snow layers are revealed. They are a result of the successive process of superposition of ice crystal-chemical symmetry and dissymmetry of the whole system. Soil-snow-atmosphere, according to the known P. Curie principle. The book is intended for glaciologists and snow scientists employed in the study of the structure of snow cover and in avalanche forecasting as well as for specialists in the field of mineralogical crystallography and crystal growth.