ballantine books bal-hi p/b edition, not a mass-market paperback edition
cover art by richard powers (unsigned, re-used from ballantine books mmpb second printing)
cover price 50¢
192pp? including titles, indicia etc, end pp.
produced for distribution through schools rather than via the mass-market distribution system
some bal-hi editions include nf essays on the specific book or on the author's fiction in general.