. The Eurypterida of New York. Eurypterida; Paleontology. --Rt. Figure 8 Limulus. Two ommatidia shown side by side, partly schematic. The thick unshaded body is the chitin- ous covering of the eye. L. lens cone, fitting into the depression of the skin. Rt. retinula. G. ganglion cell. (From Watase) Figure 9 Diagram of the compound eye of Limulus, the black, heavy line representing the ectoderm and each depression in this layer corresponding to an ommatidium. (From Watase) developed as to escape observation. There are no records as far as we are aware, either among living forms, or among the fos
. The Eurypterida of New York. Eurypterida; Paleontology. --Rt. Figure 8 Limulus. Two ommatidia shown side by side, partly schematic. The thick unshaded body is the chitin- ous covering of the eye. L. lens cone, fitting into the depression of the skin. Rt. retinula. G. ganglion cell. (From Watase) Figure 9 Diagram of the compound eye of Limulus, the black, heavy line representing the ectoderm and each depression in this layer corresponding to an ommatidium. (From Watase) developed as to escape observation. There are no records as far as we are aware, either among living forms, or among the fossil merostomes, to support the former h3^pothesis. Numerous recent crustaceans, among them the venerable Apus, either lack the facets entirely or have them so poorly developed that they are hardly noticeable,' and this fact seems well suited to shed light on the failure to detect the facets in Euryptems and Eusarcus. In some arthropods the crystalline cone assumes a transparent semiliquid state [see Watase, 1890, p. 147], and it may perhaps be assumed ^See Parker, G. H., The Compound Eyes in Crustaceans. Mus. Comp. Zool. Bui 1891. V. 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 Clarke, John Mason, 1857-1925; Ruedemann, Rudolf, 1864-1956. Albany, New York State Education Department
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Keywords: ., bookcentury1900, bookdecad, booksubjectpaleontology, bookyear1912
