The porifera and coelentera . to the Anthozoa, since they havenothing corresponding to the ventrum and dorsum of higheranimals. It must be understood that, throughout this chapter,the sulcar surface corresponds to the ventral surface of otherauthors, the asulcar or sulcular surface to the dorsal. The termssulcus and sulculus and the corresponding adjectives are due toHaddon (33). It is obvious from this description that the mouth of Hydraand its allies does not correspond morphologically with what isusually called the mouth, but rather with the inferior opening ofthe stomodaeum of the Anthozoa
The porifera and coelentera . to the Anthozoa, since they havenothing corresponding to the ventrum and dorsum of higheranimals. It must be understood that, throughout this chapter,the sulcar surface corresponds to the ventral surface of otherauthors, the asulcar or sulcular surface to the dorsal. The termssulcus and sulculus and the corresponding adjectives are due toHaddon (33). It is obvious from this description that the mouth of Hydraand its allies does not correspond morphologically with what isusually called the mouth, but rather with the inferior opening ofthe stomodaeum of the Anthozoan zooid; this being the region inboth groups at which the ectoderm passes into the endoderm. THE ANTHOZOA The Anthozoan zooid is further characterised by the followinganatomical features :—The coelenteron is not a simple cavity, asin the Hydroid zooid, but is divided by a number of radial foldsof tissue into a corresponding number of radial chambers. Theseradial folds of tissue are called mesenteries, or by German authors,. Flo. II. 1.—Section through tlie stoniotlaenm of Adamsia rondektU. UiaKnimniatic. cc, ectoilemishowing elongate ciliated epithelial cells, two kinds of gland cells, and nematocysts. Beneathtiie ectodenn is a layer of nerve tibrils. mg, niesogloea, containing tibrils and a few stellatecells; en, endodenn composed of cohnnnar ciliated cells and coiiUining two kinds of gland 2.—Ecto<lenn cells from the body wall of Corynadis riridis, partly 8.—A portion of epithelium from the tentacle of Anemoniu sidcata, consisting of tlireosupporting cells and one sense cell. cnidoblast willi enclosed neniatocyst from the tentacle of Anrnwnia sulcata. ganglion cells from the ectodenn of the peristome of .-iMfmonin suh-nta. a.—Au epithelio-musiiilar cell from the extended tentacle of Adamsia ronilcletii. fia. Thesame from a contracted tintacle. 66 and Cic Endoderm cells with symbiotic zooxanthellae fromthe tentacle of-4ii<i(io»i Mi/cfK.
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Keywords: ., bookcentury1900, bookdecade1900, booksubje, booksubjectctenophora
