The paper presents low resolution spectra in the range of 3700 to 7100 A, taken with the Royal Greenwich Observatory Image Photon Counting System on the 2.5-meter Isaac Newton Telescope, at the Observatory of El Roque de los Muchachos on the night of September 25/26, 1985. At this epoch, the Comet had a heliocentric distance of 2.41 AU. The paper also presents isophotal maps of the spatial distribution of CN, the strongest emission feature in the spectrum of Comet Halley at this epoch, and of C2. The column density distribution and total mass of CN in the coma are derived. The CN emission was found to extend more than 4 arcminutes from the nucleus on the antisun radius vector, implying an extension of at least 400,000 km in this direction. The extent of the coma in the observed molecular species is found to be consistent with scale length measures for other comets.