. The Cambridge natural history. Zoology. 442 ECHINODERMATA ASTEROIDEA the ambulacral groove, and a little below this spot a short transverse canal connects the tube-foot vyith the radial canal which lies beneath these ossicles (Fig. 191). The tube-feet are, therefore, really a double row of lateral. FiQ. 190.—A, view of the under half of a specimen of Asterias rubens, which has been horizontally divided into two halves. B, enlarged view of the axial simi.«, stone- canal and genital stolon out across. , Ambulacral ossicle ; amp, ampullae of the tube-feet; , axial sinus ; gon, gonad
. The Cambridge natural history. Zoology. 442 ECHINODERMATA ASTEROIDEA the ambulacral groove, and a little below this spot a short transverse canal connects the tube-foot vyith the radial canal which lies beneath these ossicles (Fig. 191). The tube-feet are, therefore, really a double row of lateral. FiQ. 190.—A, view of the under half of a specimen of Asterias rubens, which has been horizontally divided into two halves. B, enlarged view of the axial simi.«, stone- canal and genital stolon out across. , Ambulacral ossicle ; amp, ampullae of the tube-feet; , axial sinus ; gon, gonad ; , genital stolon ; marg, marginal ossicle ; , nerve ring ; oe, cut end of oesophagus ; pst, peri- stome ; ret, retractor muscle of the stomach ; sept, interradial septum ; stone c, stone-canal; T, Tiedemann's body ; , water-vascular ring-canal. branches of the radial canal. The appearance of being arranged in four rows is due to the fact that the transverse canals connect- ing them with the radial canal are alternately longer and shorter so as to give room for more tube-feet in a given length of the arm. Each tube-foot ends in a round disc with a slightly thickened edge. The radial canal terminates in a finger-shaped. 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 Harmer, S. F. (Sidney Frederic), Sir, 1862- ed; Shipley, A. E. (Arthur Everett), Sir, 1861-1927. ed. [London, Macmillan and Co. , Limited; New York, The Macmillan Company
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
