Platyctenida is an order of comb jellies. Platyctenida is the only benthic group of organism in the phylum Ctenophora. Ranging in size 15 cm and below, they have dorsalventrally flattened, oval bodies and secondarily bilaterally symmetrical, platyctenids look very much like nudibranchs or flatworms and are often confused for them. All but 1 species of platyctenids do not possess the iconic ctene rows (the ciliated comb-rows) that distinguishes the Ctenophores but they still possess the pair of tentilla-bearing tentacles and adhesive collocytes that also characterize the phylum in pores along the dorsal surface. They cling to and creep on surfaces by everting the pharynx and using it as a muscular "foot".