. Zoology : for students and general readers . Zoology. Fig. 905.—Sing, Ural size. Nat- Tlie group of mollusks represented by Chiton (Fig. 207, Chiton ruber) have been referred to the worms by Jhering, on account of the segmented ajspearance of the plated shell, and the nervous sys- tem, which consists of two parallel cords, connected by several commis- sures ; * as well as from the fact that the intestine ends at the hinder end of the body. The young is oval when hatch- ed, and is a trocho- sjihere, having a ciliated ring in the middle of the body with a long tuft of large cilia on the head.
. Zoology : for students and general readers . Zoology. Fig. 905.—Sing, Ural size. Nat- Tlie group of mollusks represented by Chiton (Fig. 207, Chiton ruber) have been referred to the worms by Jhering, on account of the segmented ajspearance of the plated shell, and the nervous sys- tem, which consists of two parallel cords, connected by several commis- sures ; * as well as from the fact that the intestine ends at the hinder end of the body. The young is oval when hatch- ed, and is a trocho- sjihere, having a ciliated ring in the middle of the body with a long tuft of large cilia on the head. Afterwards it becomes segmented, as in Fig. 208, and is remarkably worm-like, the limestone plates of the adult corre- sponding to the primitive larval rings. Certain Gastropods are useful either as food or in the arts. In Europe Littorina littorea, the limpet {Patella ofl^n'alirjfye'f o/fopKc vulgata), the whelk {Buccimmi un- °''™' «, olfactory ne™. datum), and the garden-snail {Helix hortensis) are eaten. The sea-ear {Haliotis) is roasted in the shell. The animal of Cyniha, Stromlus gi- gas, Turt)0, Troclius, and Conus are eaten in the tropics, while many of the larger forms are used for fisli- bait. Pearls are sometimes found in the species of Haliotis and Turho. The beautiful shell of Cassis is made into cameo pins, and the shell of Stromhus gigas is in the West Indies made into ornaments. * In Fissurella and Haliotis the two nerve-cords from the pedal gan- glia are also united by nine transverse commissures, so that here also we have an approach to the double ganglionated cord of 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 Packard, A. S. (Alpheus Spring), 1839-1905. New York : Henry Holt
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1879
