A manual of zoology, Volum 1 |
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abdomen actinosoma Actinozoa adult alimentary canal ambulacral amongst animal Annelida antennæ anus aperture appendages Arachnida arms attached bivalve body Brachiopoda branchiæ buds calcareous called carapace cavity cephalothorax chamber chitinous ciliated cœnosarc composed comprising consists contractile coral corallum Crustacea Ctenophora developed disc distinct division dorsal Echinodermata entirely external extremity filaments foot Foraminifera ganglia Gasteropoda gemmation genera gills gonophores head horny hydrosoma Hydrozoa individual Infusoria Insects integument intestine known labium larva limbs locomotive male mandibles mantle margin maxillæ membranous Mollusca mouth muscular nectocalyces nervous system operculum organised organs ovum pair Paleozoic parasitic perforated plates Pneumatocyst polypes polypites Polyzoa possess posterior produced Protozoa reproductive resemble respiratory Rocks Rotifera rudimentary sarcode Scolecida segments septa shell Silurian single siphons siphuncle somites species spiral sponges stomach structure sub-class sub-kingdom Sub-order suctorial surface tentacles termed thorax tube usually valves ventral vesicles whilst wings Zoantharia zoöids
Populære avsnitt
Side 200 - Three, or perhaps, in some cases, more, somites unite and become specially modified to form the thorax, to which the three pairs of locomotive limbs, characteristic of perfect Insects, are attached.
Side 11 - These sub-kingdoms are further subdivided into classes; classes are divided into orders; orders into families; families into genera; and genera into species.
Side 189 - The respiratory organs, however, whenever these are differentiated, are never in the form of branchise as in the Crustacea, but are in the form either of pulmonary vesicles or sacs, or of ramified tubes, formed by an involution of the integument, and fitted for breathing air directly. Further, there are never " more than four pairs of locomotive limbs, and the somites of the abdomen, even when these are well developed, are never provided with limbs ; " the reverse being the case amongst the Crustacea.
Side 176 - Carapace flask-shaped; body formed of one cephalic, seven thoracic, and three abdominal segments, the latter bearing three pairs of cirri, but the thoracic segments being without limbs. Mouth, with the labrum greatly produced,, and capable of independent movements.
Side 212 - The Termitarium has no external aperture for ingress or egress, as far as can be seen, the entrance being placed at some distance, and connected with the central building by means of covered ways and galleries. Each Termitarium is composed of " a vast number of chambers and irregular intercommunicating galleries, built up with particles of earth or vegetable matter, cemented together with the saliva of the insects.
Side 11 - Species. — No term is more difficult to define than " species," and on no point are zoologists more divided than as to what should be understood by this word. Naturalists, in fact, are not yet agreed as to whether the term species expresses a real and permanent distinction, or whether it is to be regarded merely as a convenient, but not immutable abstraction, the employment of which is necessitated by the requirements of classification. By Buffon, "species " is defined as " a constant succession...
Side 45 - the foraminiferous fauna of our own seas probably presents a greater range of variety than existed at any preceding period ; but there is no indication of any tendency to elevation towards a higher type.
Side 254 - The members of this order are defined as follows: — "Abdomen well developed, and protected by a shell, into which the whole animal can usually retire. Mantle forming a vaulted chamber over the back of the head, in which are placed the excretory orifices, and in which the branchiae are almost always lodged. Branchice pectinated or plume-like, situated (proson) in advance of the heart. Sexes distinct
Side 80 - From the above description,' he writes, 'it will be evident that the Medusa is in all essential respects identical in structure with the free-swimming generative bud or gonophore of many of the fixed and oceanic Hydrozoa. Indeed, a great many Forms which were previously included in the Medusldae have now been proved to be really 1 Manual of Zoology, General Introduction, n.
Side 29 - Until recently the great majority of naturalists believed that species were immutable productions. and had been separately created. This view has been ably maintained by many authors. Some few naturalists, on the other hand, have believed that species undergo modification, and that the existing forms of life are the descendants by true generation of pre-existing forms.