. The Cambridge natural history. Zoology. Fig. 141.âA, Hypostome of Sronteus polyactin, Ang. showing maculae, x 4. \ila, of Bronteus irradians, LmAst. x 12. (After Lindstrom.) B, Left entire surface of a macula is smooth and glossy; in others either the whole or a part is covered with granules, and in the latter case the granules may be limited to the internal third (Fig. 141, B) or to the central portion. Sections of a macula show that the granules are really globular lenses similar to those of the compound eyes on the dorsal surface of the head. Some of the maculae wliich are without len
. The Cambridge natural history. Zoology. Fig. 141.âA, Hypostome of Sronteus polyactin, Ang. showing maculae, x 4. \ila, of Bronteus irradians, LmAst. x 12. (After Lindstrom.) B, Left entire surface of a macula is smooth and glossy; in others either the whole or a part is covered with granules, and in the latter case the granules may be limited to the internal third (Fig. 141, B) or to the central portion. Sections of a macula show that the granules are really globular lenses similar to those of the compound eyes on the dorsal surface of the head. Some of the maculae wliich are without lenses show no structure, but in otliers there is a spongy or irregularly polyhedric structure with prisms, resembling the marginal zone of the prismatic eyes of some genera. There â seems no doubt that the maculae with lenses are visual organs, and those without are degenerate eyes. They occur in some genera which, according to Lindstrom, are without eyes on the dorsal surface. Maculae do not appear to l^e present in other Crustacea, but they have been compared with a median organ, found just in front of the hypostome in Branchipus} Maculae ' Spencer, Geol. Mag. 1903, p. 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
