A diverse assemblage of Middle Cambrian sponges, recently collected from the Wheeler and Marjum Formations of western Millard County, Utah, includes a variety of demosponges and hexactinellids. This collection includes the verongiid Vauxia bellula Walcott, 1920, and the protomonaxonids Choia carteri and Choia ridleyi Walcott, 1920, Hamptonia bowerbanki Walcott, 1920, and Hamptonia parva n. sp. Hexactinellids in the collection include the reticulosid protospongioids Diagoniella hindei Walcott, 1920, and Diagoniella magna n. sp.; the dierespongioid hydnodictyid Valospongia? gigantus Rigby, 1973; and the hintzespongioid Hintzespongia bilamina Rigby and Gutschick, 1976. A specimen of the problematic Sentinelia? draco Walcott, 1920, is also documented as part of the collection.

The modest faunule of silicified fossil demosponges, documented here, was recovered from the Upper Ordovician Montgomery Limestone in the Taylorsville area, in the northern Sierra Nevada of northern California. Included are specimens of the ceractinomorph angullongiid Amblysiphonelloidea tubulara Rigby & Potter, 1986, the girtyocoelliid Girtyocoeliana epiporata (Rigby & Potter, 1986), the sebargasiid Amblysiphonella sp., and the cliefdenellids Cliefdenella alaskaensis Stock, 1981, and Rigbyetia obconica (Rigby & Potter, 1986). In addition, specimens of the vaceletiid Corymbospongia adnata Rigby & Potter, 1986, are described and figured. The assemblage is closely related to faunules of sphinctozoan sponges earlier reported by Rigby & Potter (1986) from the eastern Klamath Mountains, to the west in northern California

Relatively common specimens of the hypercalcified agelasiid sponge Hormospongia labyrinthica Rigby and Blodgett, 1983 and specimens of associated species of Hormospongia have been previously reported from Emsian and Eifelian stratigraphic units at several localities in south-central and southeastern Alaska (Rigby and Blodgett, 1983). Those sponges were first described from the type section of the Eifelian Cheeneetnuk Limestone in the McGrath A-5 quadrangle. Since then several additional specimens of Hormospongia labyrinthica have also been collected from a new locality in the Talkeetna C-6 quadrangle in south-central Alaska (Figs. 1, 2.1), and are documented here.