Description of Glaucomides bromelicola n. gen., n. sp. (Ciliophora, Tetrahymenida), a macrostome forming inhabitant of bromeliads (Bromeliaceae), including redescriptions of Glaucoma scintillans and G. reniformis.

Glaucomides bromelicola n. gen., n. sp. is a tetrahymenid ciliate common in tank bromeliads of Central and South America. The new genus is characterized by having a kinety fragment along the left mouth margin, an unciliated dorsolateral area, a tetrahymenid silverline pattern, and the ability to produce macrostomes when bacterial food is depleted. I provide a detailed description of the microstome and the macrostome morph, using several morphological methods. This showed that G. bromelicola does not belong to the Glaucomidae, but to the Bromeliophryidae. However, various morphological traits are highly similar to those of Glaucoma reniformis and G. scintillans, which are thus redescribed and compared with G. bromelicola. Most differences are inconspicuous, showing that new tetrahymenids must be described very carefully. The morphological and molecular data suggest a common ancestor for Glaucoma and Glaucomides, both performing their own radiation, the former in ordinary limnetic habitats, the latter in tank bromeliads.

Agolohymena aspidocauda nov. gen., nov. spec., a histophagous freshwater tetrahymenid ciliate in the family Deltopylidae (Ciliophora, Hymenostomatia), from Idaho (northwest USA): morphology, ontogenesis and molecular phylogeny.

Morphology, ontogeny and the molecular phylogeny of Agolohymena aspidocauda nov. gen., nov. spec., a new freshwater tetrahymenid ciliate from Idaho, U.S.A, are described. The ontogeny and histophagous mode of nutrition are similar to those of Deltopylum rhabdoidesFauré-Fremiet and Mugard, 1946. The new genus is placed with Deltopylum in the resurrected family Deltopylidae Song and Wilbert, 1989. We emend the diagnostic features of the family to include division by polytomy, right and left somatic kineties extending into the preoral suture, crook-shaped or sigmoid adoral membranelles 1 and 2, markedly reduced adoral membranelle 3 and a tetrahymenid silverline pattern. The main diagnostic features of the new genus are a disc-shaped caudal ciliary array and formation of two types of resting cysts, one smooth and the other bearing tangled tubular or cylindrical lepidosomes. Nuclear small subunit ribosomal RNA gene and mitochondrial cytochrome oxidase subunit 1 gene sequences place the new genus basal within the order Tetrahymenida, well separated from members of the family Tetrahymenidae (Lambornella and Tetrahymena) and also from other tetrahymenids (Colpidium, Dexiostoma, Glaucoma). The genetic divergences between this species and other genera in Tetrahymenida are large enough to suggest placement of the new genus in a separate family. This corroborates the morphological data, since the elaborate caudal ciliary array and the lepidosome-covered resting cyst of this species are not found in other Tetrahymenidae.