Systematics and phylogeny of the cheilostome bryozoan Doryporella

The four nominal species of the Arctic-Boreal anascan bryozoan Doryporella Norman are revised. Colonies of Doryporella are small, typically encrust sh ells and pebbles, and have autozooids with frontal walls bearing a distinct ive reticulate pattern of polygonal ridges. High resolution SEM shows the f rontal wall to be an interior wall (cryptocyst), contrary to previous studi es which have regarded it as an exterior wall (gymnocyst). The inter-relati onships between the species assigned to Doryporella are assessed cladistica lly using skeletal characters. The type species (D. spathulifera) and two o ther species (D. alcicornis and D. armata) form a well-supported clade, but the fourth species (D. reticulata) is more closely-related to certain othe r calloporid genera. Therefore, the reticulate frontal wall is inferred to have evolved twice and D. reticulata is removed to Doryporellina gen. n. Bi ogeographical distributions of the four species are reviewed.