Phylum Sentence Examples

The terms used for indicating groups are " Phylum " for the large diverging branches of the genealogical tree as introduced by Haeckel, each Phylum bears secondary branches which are termed " classes," classes again branch or divide into orders, orders into families, families into genera, genera into species.

The Phylum Appendiculata similarly branches into sub-phyla, viz.

Vertebrate palaeontologists were slow to grasp this principle; while the early speculative phylogenies of the horse of Huxley and Marsh, for example, were mostly displayed monophyletically, or in single lines of descent, it is now recognized that the horses which were placed by Marsh in a single series are really to be ranged in a great number of contemporaneous but separate series, each but partially known, and that the direct phylum which leads to the modern horse has become a matter of far more difficult search.

They are not, therefore, like the wings of birds, modified from some pre-existing structures (the fore-limbs) common to their phylum; they are new and peculiar structures.

The suggestion to place Brachiopods with the Polyzoa, Phoronis, Rhabdopleura and Cephalodiscus, in the Phylum Podaxonia made in Ency.

The correctness of this association is questionable, and the Polyzoa are here treated as a primary division or phylum of the animal kingdom.

The phylum is subdivided as follows.

This revolution may be accomplished by adding the term " mutation ascending " or " mutation descending " for the minute steps of transformation, and the term phylum, as employed in Germany, for the minor and major branches of genetic series.

The inter-relationships of the three members of the Platyelmia are of a more doubtful nature than is the unity of the phylum.

Formerly, they were gener ally arranged amongst the Platyelminthes as 2 a sub-order in the order of the Turbellarians, but with the advance of our knowledge of these lower worms it has been found desirable to separate them from the Turbellarians and to look upon the Nemertina as a separate phylum.

As the Turbellaria (Planarians) are the most primitive division of the Platyelmia, the problem of the affinities of this phylum resolves itself into that of the relationships of the Turbellaria.

The group is an isolated one and should probably be regarded as a separate phylum.

There is no doubt that the phylum of Angiosperms has not sprung from that of Gymnosperms.

Ray Lankester (preface to the English edition of C. Gegenbaur's Comparative Anatomy), and employed by the same writer in the 9th edition of this encyclopaedia (article "Zoology") to denote the eighth phylum, or major division, of coelomate animals.

In the Dentaliidae the mouth is surrounded by eight small lobes, but these are absent in the 1 For a discussion of its relationship to the other classes of the Phylum see Mollusca.

The line of descent of recent cycads is comparatively clear in so far as they have undoubted affinity with Palaeozoic plants which combined cycadean and filicinean features; but opinion is much more divided as to the nature of the phylum from which the conifers are derived.

It is not improbable that the three genera of this ancient phylum survive as types of a blindly-ending branch of the Gymnosperms; but be that as it may, it is in the Gnetales more than in any other Gymnosperms that we find features which help us to obtain a dim prospect of the lines along which the Angiosperms may have been evolved.

The hard calcareous substance to which the name coral is applied is the supporting skeleton of certain members of the Anthozoa, one of the classes of the phylum Coelentera.

Of late years an opinion is gaining ground that they may be regarded as constituting collectively an independent phylum of their own (Graptolithina).

Klein (1734) to denote the tests of the Echini or sea-urchins; its later use for the animals themselves, or for the whole phylum, was an error in both history and etymology.

Now ensued the great event that originated the phylum - the discovery of the sea-floor.

The most important positive evidence on this point indicates that the most ancient Gymnosperms were derived from the Filicales rather than from any other phylum of the Vascular Cryptogams. Extinct forms are known intermediate between the Ferns and the Cycads, and a number of these have been shown to bear seeds and must be classed as Pteridospermae.

Caldwell's views were accepted by Lankester (8) in the 9th edition of this work, the Phylum Podaxonia being there instituted to include the groups just mentioned, together with the Pterobranchia.

Some authors have been so much impressed by the similarity of this extinct family to the Cycads, that they have regarded them as being on the direct line of descent of the latter group; it is more probable, however, that they formed a short divergent phylum, distinct, though not remote, from the Cycadean stock.

The phylum Chytridiomycota has traditionally been characterized on the basis of motile cells with a single posterior flagellum.

In abundance of species the mollusks constitute the largest invertebrate phylum apart from the Arthropods with over 50,000 described species.

This new species was such an unusual organism, a new phylum was proposed.

The general purpose is to give something like an equivalence of importance to divisions or branches indicated by the same term, but it is not intended to imply that every phylum has the Ursprung der Wirbelthiere (Leipzig, 1875); and Lankester, Degeneration (London, 1880),, ti, ae / .r ?

Arthropods are invertebrates belonging to the phylum Arthropoda, the jointed-leg, spineless creatures of the world.

For a discussion of the relationship of the Gastropoda to the remaining classes of the phylum, see MoLLUSCA.

Affinities.-The position of the Nemertines in the animal kingdom is now looked upon as more isolated than was formerly thought, and recent writers have been inclined to treat them as a separate phylum.

The Metazoa form two main branches; one, Parazoa, is but a small unproductive stock comprising only the Phylum Porifera or Sponges; the other, the great stem of the animal series Enterozoa, gives rise to a large number of diverging Phyla which it is necessary to assign to two levels or grades - a lower, Enterocoela (often called Coelentera), and a higher, Coelomocoela (often called Coelomata).

P. Lamarck's term Annelides, now used to denote a major phylum or division of coelomate invertebrate animals.

The main limitations of the sub-kingdom or phylum Mollusca, as laid down by Cuvier, and the chief divisions thus recognized within its limits by him, hold good to the present day.

Increase of knowledge has now, however, established the conclusion that the agreement of structure supposed to obtain between Polyzoa and true Mollusca is delusive; and accordingly they, together with the Brachiopoda, were removed from the Molluscan phylum by Lankester in his article in the 9th edition of this work (on the which present article is based).

Crustaceans The largest Phylum of invertebrate animals is the Arthropoda containing the crustaceans The largest Phylum of invertebrate animals is the Arthropoda containing the crustaceans with over 50,000 marine species.

Every great group or phylum of vascular plants, when it has become dominant in the vegetation of the world, has produced members with the tree habit arising by the formation of a thick woody trunk, in most cases by the activity of a cambium.

From the preceding discussion an idea may be formed of the primitive characters of the Phylum (From Gegenbaur.) FIG.