NGC 5128 (Cen A) has been known for many years as a peculiar elliptical, but only recently has it been recognized as the prototype of a new class of object (Bertola and Galletta 1978). This class of galaxy is characterized by an elliptical-like stellar body crossed along the minor axis by a dust lane, and was comprised initially of five objects. The class was extended in a remarkable way by Hawarden et al. (1981), who drew attention also to the existence of ellipticals with the dust lane along the major, and along intermediate axes. Ninety objects are now listed as dust lane ellipticals in the compilation by Ebneter and Balick (1985) and its updated version Ebneter 1986).
Kotanyi and Ekers (1979) pointed out the tendency of the dust lane to align perpendicularly to the radio source, when present.
Since 1978 it has been realized that the study of this type of object could lead to important information on the intrinsic shape of elliptical galaxies. In fact there is no a priori reason for these galaxies to be oblate spheroids (Binney 1978) since in many cases their rotational velocity is too low to generate a flattened system (Bertola 1972, Bertola and Capaccioli 1975, Illingworth 1977).
The dust lane silhouetted against the luminous body of the galaxy, which otherwise would be classified as a pure elliptical, is interpreted as a disk or a ring seen almost edge-on, the result of a past capture by an early type galaxy of a gas rich system. It is therefore clear that the observed configuration depends on the intrinsic shape of the elliptical galaxy and on the impact parameters.
In this paper we shall describe the morphological, statistical, kinematical, and photometric properties, of the elliptical galaxies with dust lanes.