Abstract. It is proved that if every cyclic right /^-module is torsionless and R is a left CS-ring then R is semiperfect left continuous with soc(R R ) essential in R R. As a consequence every right cogenerator, left CS-ring R is shown to be right pseudo-Frobenius and left continuous, and an example is given to show that R need not be left selfinjective. It is also proved that if R is a left CS-ring and every cyclic right /^-module embeds in a free module, then R is quasi-Frobenius if and only if J(R) c Z(R R ).
Introduction.Right CS-rings with certain cogenerating (annihilator) conditions were considered by Gomez-Pardo and Guil Asensio in [10] and [11]. For example they show that if R is a right CS-ring and every cyclic (finitely generated) right 7?-module embeds in a free module then R is right artinian (quasi-Frobenius). They also prove that if R is a right cogenerator right CS-ring then R is right pseudo-Frobenius.In this paper we consider these same classes of rings but with the left CS-condition rather than the right CS-condition. We show that if R is a left CS-ring and every cyclic right /^-module is torsionless, then R is a semiperfect left continuous ring with SOC(RR) C.