roughly into two-tone and three-tone systems. Tongass Tlingit, however, has no tone but a four-way register contrast between short, long, glottalized, and "fading" vowels. (In the last type, the onset of the vowel is articulated normally but the release is murmured, essentially a rapid opening of the glottis once articulation is begun.) The tone values in two-tone dialects can be predicted in some cases from the three-tone values but not the reverse. Earlier, it was hypothesized that the three-tone dialects were older and that the two-tone dialects evolved from them. However, Jeff Leer's discovery of the Tongass dialect in the late 1970s has shown that the Tongass vowel system is adequate to predict the tonal features of both the two-tone and three-tone dialects, but none of the tonal dialects could be used to predict vocalic feature distribution in Tongass Tlingit. Thus, Tongass Tlingit is the most conservative of the various dialects of Tlingit, preserving contrasts which have been lost in the other dialects. The fading and glottalized vowels in Tongass Tlingit have also been compared with similar systems in the Coast Tsimshian dialect. However, Krauss and Leer (1981, p. 165) point out that the fading vowels in Coastal Tsimshian are the surface realization of underlying sequences of vowel and glottalized sonorant, . That is in contradistinction to the glottal modifications in Tongass Tlingit, which Leer argues are symmetric with the modifications of the consonantal system. Thus, a fading vowel is symmetric with an aspirated consonant , and a glottalized vowel is symmetric with an ejective (glottalized) consonant . That implies that the two systems have no familial relationship. Leer (1978) speculated that the maintenance of the pretonal system in Tongass Tlingit was caused by the proximity of its speakers around the Cape Fox area near the mouth of the Portland Canal to speakers of Coastal Tsimshian, just to the south. Phonology Tlingit has a complex phonological system compared to Indo-European languages such as English or Spanish. It has an almost complete series of ejective consonants accompanying its stop, fricative, and affricate consonants. The only missing consonant in the Tlingit ejective series is . The language is also notable for having several laterals but no voiced and for having no labials in most dialects, except for and in recent English loanwords. Consonants Consonants in the popular orthography are given in the following table, with IPA equivalents in brackets. Marginal or historical