The chains are straight and rigid. The apertures have an elliptical to oval shape. Sibling setae are fused only at the point where they exit from the margin, and these setae exhibit clear transverse rows of pores. In a broad girdle view, the terminal setae are consistently divergent along their entire length. Resting spores have a primary valve with two conical protuberances that branch out repeatedly and dichotomously at the tips. The secondary valve is smooth.