A note on chromospheric fine structure at active region polarity boundaries.

High resolution H-alpha filtergrams from Big Bear Solar Observatory reveal that some filamentary features in active regions have fine structure and hence magnetic field transverse to the gross structure and the zero longitudinal field line. These features are distinct from the usual active region filament, in which fine structure, magnetic field, and filament are all parallel to the zero longitudinal field line. The latter occur on boundaries between regions of weaker fields, while the former occur at boundaries between regions of stronger field.