The most important difference between the two guides is inherent in our catalog being a later compilation, including all galaxies observed by IUE that fulfill the selection criteria. The improved extraction procedures of INES resulted in much less noise in the spectrum of a galaxy, in comparison to the spectra presented by Longo & Capaccioli (1992). Furthermore, the method of combining the SW and LW spectra of one object is different; we tried to match the blue end of the LW to the ``red'' end of the SW by averaging regions of overlap and adding a constant to the LW spectrum, thus the spectra we present are, by definition, smoothly joined.
Longo & Capaccioli (1992) decided to correct the spectra they plotted in the ULDA Access Guide No. 3 for Galactic extinction. They used the Burstein & Heiles (1984) color excess and the Seaton (1979) average extinction curve. It is obvious today that the Galactic extinction is extremely patchy, even when using the improved extinction from Schlegel et al. (1998); we decided therefore not to correct the spectra for galactic extinction.
The present guide contains 274 objects, approximately twice the number of galaxies included in the ULDA guide of normal galaxies. Therefore, it offers a much wider sample of objects for comparison than the previous publication. On the other hand, the same problem that plagued the derivation of template UV spectra of galaxies by Storchi-Bergman et al. (1994) still remains; in many cases the IUE aperture samples only the innermost regions of galaxies.