. Handbook of zoology [microform] : with examples from Canadian species, recent and fossil :. Zoology; Invertebrates; Zoologie; Invertébrés. 102 PROVINCE MOLLUSC A. they form a series parallel with the three orders of Protozoa amoig the Radiates. The names ard subdivisions, ho' ^ev r, remain the same under either view. The Pteropods are also regarded by some as a distinct class from Gasteropods, but they seem more properly to constitute tlie lowest order of that class, which without them would not be complete. Class 1.—Heterobranciiiata. Animals mostly attached^ a: d often aggregative in commu
. Handbook of zoology [microform] : with examples from Canadian species, recent and fossil :. Zoology; Invertebrates; Zoologie; Invertébrés. 102 PROVINCE MOLLUSC A. they form a series parallel with the three orders of Protozoa amoig the Radiates. The names ard subdivisions, ho' ^ev r, remain the same under either view. The Pteropods are also regarded by some as a distinct class from Gasteropods, but they seem more properly to constitute tlie lowest order of that class, which without them would not be complete. Class 1.—Heterobranciiiata. Animals mostly attached^ a: d often aggregative in communities ; destiiuteofo: ^ ins o^ special sense. Heart simple or at once systemic and branchial. No special respiratory organs. Food obtained by ciliated tentacular A B C Diagrams of Hetkrobranchiates. (A) Polyzoon; (B) Tunicate; (C) ISrachiopod. (a) Mouth; (s) Stomach; (o) Ovaries. The simplest of these Molluscoids, the moss animals or Bryozoa or Polyzoa, are as far removed in grade of complexity from the more typical MoUusks as the Rhizopods are from typical Radiates. Yet natura- lists have long been convinced that they must be reckoned as humble Mollusks. The other groups. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Dawson, J. W. (John William), Sir, 1820-1899. Montreal : Dawson
Size: 2151px × 1162px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1870
