The authors of this Communication wish to alter the proposed structure of annulene 1, a system that had previously been reported by Yamaguchi et al. [1] After one of the authors (F.M.M.) had originally inspected the then available analytical data ( 1 H and 13 C NMR spectra, elemental analysis, and ESI-MS data), he affirmed that they were (and still are) consistent with the annulene system. In particular, parent mass spectral signals at m/z 531.44353, 587.50648, and643.56867 for the R = C 12 H 25 , C 14 H 29 , andC 16 H 33 derivatives, respectively, all correspond to the mass of [1ÀCl À ] + . Recently, however, Prof. M. Cristl suggested [2] that the pyridinium salt 2 would be an alternative and more likely possibility. There exists an intriguing ambiguity in this case because 1 and 2 have indistinguishable NMR spectra and elemental analyses and because our [1À2 Cl À ] 2+ base peak and the [2ÀCl À ] + parent peak happen to have identical masses. We are now able to differentiate the two structures through weak 13 C-containing MS signals. These signals have a shift one mass unit higher than the all-12 C signal (consistent with [2ÀCl À ] + ) as opposed to 0.5 units higher (consistent with [1À2 Cl À ] 2+ ). In view of these new data, our peaks at m/z > 500 must, we surmise, arise from dimers of 2 in the gas phase. Fortunately, the altered identity of the compound in no way affects our high-level calculations on the annulene structure. Moreover, our conclusion based on the NMR data, namely, that the terminal methyl groups of the chains loop within a micelle so as to contact the micelle surface, remains valid, although the micelles are now more classical in nature than we had previously envisioned.