  (Abridged) Galaxies with polar rings (PRGs) are a unique class of
extragalactic objects allowing to investigate a wide range of problems, linked
with the formation and evolution of galaxies, and to study the properties of
their dark haloes. The progress in the study of PRGs is constrained by a small
number of known objects of this type. Up to date, we can only attribute about
two dozens of kinematically-confirmed galaxies to this class, mostly from
Whitmore et al. (1990) catalogue. We present a new catalogue of PRGs based on
the results of the original Galaxy Zoo project. Based on the preliminary
classification of the Galaxy Zoo, we viewed more than 40000 images of the Sloan
Digital Sky Survey (SDSS) and selected 275 galaxies, included in our catalogue.
Our Sloan-based Polar Ring Catalog (SPRC) contains 70 galaxies that we
classified as "the best candidates", among which we expect to have a very high
proportion of true PRGs, and 115 good PRG candidates. 53 galaxies are
classified as PRG related objects.We identified 37 galaxies that have their
presumed polar rings seen almost face-on. The SPRC objects are on the average
fainter and located further away than the galaxies from the catalog by Whitmore
et al., although our catalogue does include dozens of new nearby candidate
PRGs. The new catalogue significantly increases the number of genuine PRG
candidates, and may serve as a good basis both for the further detailed study
of individual galaxies, and for the statistical analysis of PRGs as a separate
class of objects. We performed spectroscopic observations of six galaxies from
the SPRC at the 6-m telescope. The existence of polar rings was confirmed in
five galaxies, and one object appeared to be a projection of a pair of
galaxies. Adding the literature data, we can already classify 10 galaxies from
our catalogue to the kinematically-confirmed PRGs.
