FIG. 4. — A-U in Rise of subgen. Rhoicosphenula Lange-Bert. to the genus level, and description of a new Gomphosphenia s.s. species from Puerto Rico

FIG. 4. — A-U, Light micrographs of Gomphosphenia patrickiana Cantonati, Lange-Bert., Kociolek & A.A.Saber, sp. nov., depicting the valve size-diminution series and girdle view of the holotype specimens. Scale bar: 10 μm.