As against Realism he maintains consistently Res de re non praedicatur; genera and species, therefore, which are predicated of the individual subject, cannot be treated as things or substances.
Neomenia and other genera have no salivary glands.
It had already been understood that the various genera of the Ratitae were the representatives of so many different groups, each of which was at least equivalent to ordinal rank, and that therefore, if the Ratitae were still to be considered a natural group, this common ancestry must be referred to a remote geological epoch.
After the determination of a number of cosmopolitan insects that may well have been artificially introduced, there remains a large proportion of endemic species - sometimes referable to distinct genera - which suggest a high antiquity for the truly insular faunas.
Finally the genera Pinguicula, Utricularia, Genlisea and Polypompholix belong to the gamopetalous order Lentibulariaceae.
Giesbrecht, displacing the older name Ascomyzontidae, assigns to this family 21 genera in five subfamilies, and suggests that the long-known but still puzzling Nicothoe from the gills of the lobster might be placed in an additional subfamily, or be made the representative of a closely related family.
Magnolia, Aucuba, Abelia and Skimmia may be mentioned as examples of Chinese genera found in the eastern Himalayas, and the tea-tree grows wild in Assam.
So-called senseclubs or cordyli found in a few Leptomedusae, especially in those genera in which otocysts are inconspicuous or absent (fig.
These two genera may be regarded as forming the earliest stages in the evolution of the horse, coming below Hyracotherium (see Equidae).
In the Stylasteridae sessile gonophores are formed, always by budding from the coenosarc. In Distichopora the gonophores have radial canals, but in other genera they are sporosacs with no trace of medusoid structure.