-1- CONSTRAINING HIGH TONE SPANS IN EKEGUSII VERBAL TONOLOGY Lee S. Bickmore University at Albany, SUNY 0. Introduction Ekegusii, a Bantu language spoken in southwestern Kenya, exhibits a wide range of tonal patterns in the finite verbal system. 1 Of the four logical types of tonal phenomena defined by crossing the parameters of displacement vs. spread and bounded vs. unbounded, three are attested in Ekegusii: 1) bounded High displacement, the delinking of a High and relinking it to an adjacent Tone Bearing Unit (TBU), 2) bounded High spreading , the spreading of a High to an adjacent TBU, as well as 3) unbounded High spreading, the spreading of a H to the ma ximal number of free TBUs in a certain direction. While these are all productive phonological processes, they are blocked from applying in certain configurations. To help account for the occurrence of these three tonal processes, I will argue that Ekegusii has both linked Highs and floating Highs, and that their tonal behavior is distinct in crucial respects. I will show that the complex array of surface tonal patterns results from a delicate interplay between the productivity of various tonal processes and the avoidance of certain tonal structures. Making use of a constraint ranking within Optimality Theory as described in McCarthy & Prince (1993a-b), Prince & Smolensky (1993) and as refined in subsequent work, I will provide a complete account of the Ekegusii facts. Several issues of theoretical importance arise. First, I show that there are two distinct lexical domains (the phonological stem and