{"article":{"id":"britannica-11-al-r","work_id":"britannica-11","title":"Al R","normalized_title":"al-r","slug":"al-r","aliases":[],"subtitle":"Internet Archive OCR import","body_text":"AL R, Anterior lateral rod or tendon. Natural size. (From Lankester, Q. J. Hie. Set.. N5. ml. niv.. 1884.) Limulus an Arachnid. — Modern views as to the classification and affinities of the Arachnida have been determined by the demonstration that Limulus and the extinct Eurypterines (Pterygotus, &c.) are Arachnida; that is to say, are identical in the structure and relation of so many important parts with Scorpio, whilst differing in those respects from other Arthropoda, that it is impossible to suppose that the identity is due to homoplasy or convergence, and the conclusion must be accepted that the resemblances arise from close genetic relationship. The view that Limulus, the king-crab, is an Arachnid was maintained as long ago as 1829 by Strauss-Dtirckheim (1), on the ground of its possession of an internal cartilaginous sternum — also possessed by the Arachnida (see figs, i, 2, 3, 4, 5 and 6) — and of the similarity of the disposition of the six leg-like appendages around the mouth in the two cases (see figs. 45 and 63). The evidence of the exact equivalence of the segmentation and appendages of Limulus and Scorpio, and of a number of remarkable points of agreement in structure, was furnished by Ray Lankester in an article published in 1881 (\" Limulus an Arachnid,\" Quart. Journ. Micr. Set. vol. xxi. N.S.), and in a series of subsequent memoirs, in which the structure of the entosternum, of the coxal glands, of the eyes, of the veno-pericardiac muscles, of the","body_html":"

AL R, Anterior lateral rod or tendon. Natural size. (From Lankester, Q. J. Hie. Set.. N5. ml. niv.. 1884.) Limulus an Arachnid. — Modern views as to the classification and affinities of the Arachnida have been determined by the demonstration that Limulus and the extinct Eurypterines (Pterygotus, &c.) are Arachnida; that is to say, are identical in the structure and relation of so many important parts with Scorpio, whilst differing in those respects from other Arthropoda, that it is impossible to suppose that the identity is due to homoplasy or convergence, and the conclusion must be accepted that the resemblances arise from close genetic relationship. The view that Limulus, the king-crab, is an Arachnid was maintained as long ago as 1829 by Strauss-Dtirckheim (1), on the ground of its possession of an internal cartilaginous sternum — also possessed by the Arachnida (see figs, i, 2, 3, 4, 5 and 6) — and of the similarity of the disposition of the six leg-like appendages around the mouth in the two cases (see figs. 45 and 63).

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The evidence of the exact equivalence of the segmentation and appendages of Limulus and Scorpio, and of a number of remarkable points of agreement in structure, was furnished by Ray Lankester in an article published in 1881 (" Limulus an Arachnid," Quart. Journ. Micr. Set. vol. xxi. N.S.), and in a series of subsequent memoirs, in which the structure of the entosternum, of the coxal glands, of the eyes, of the veno-pericardiac muscles, of the

","volume_id":"britannica-11-v2","page_range_label":"Vol. 2, pp. 287-287","source_url":"https://archive.org/details/encyclopaediabri02chisrich/page/n310/mode/1up","text_source_url":"https://archive.org/download/encyclopaediabri02chisrich/encyclopaediabri02chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabri02chisrich","quality_status":"ocr-imported-page-aligned","parser_version":"ia-djvu-xml-v1","page_refs":[{"page_number":"287","label":"p. 287","image_url":"/source-assets/scans/britannica-11/encyclopaediabri02chisrich/encyclopaediabri02chisrich_0311.jpg","source_image_url":"https://archive.org/download/encyclopaediabri02chisrich/encyclopaediabri02chisrich_jp2.zip/encyclopaediabri02chisrich_jp2%2Fencyclopaediabri02chisrich_0311.jp2&ext=jpg","source_url":"https://archive.org/details/encyclopaediabri02chisrich/page/n310/mode/1up"}]},"work":{"id":"britannica-11","slug":"britannica-11","title":"Encyclopaedia Britannica","short_title":"Britannica 11th","edition":"11th edition","publisher":"Cambridge University Press","publication_start_year":1910,"publication_end_year":1911,"language":"English","country":"United Kingdom / United States","copyright_status_note":"First published before 1931; treated as public domain in the United States. Verify jurisdiction before redistribution outside the U.S.","source_quality":"mixed-clean-and-ocr","text_source_url":"https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica","scan_source_url":"https://archive.org/details/encyclopaediabri","volumes":[{"id":"britannica-11-v1","volume_number":"1","title":"A to Androphagi","year":1910,"source_url":"https://archive.org/details/encyclopaediabri01chisrich","text_source_url":"https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica","scan_source_url":"https://archive.org/details/encyclopaediabri01chisrich","page_count":1084},{"id":"britannica-11-v2","volume_number":"2","title":"Andros to Austria","year":1910,"source_url":"https://archive.org/details/encyclopaediabri02chisrich","text_source_url":"https://archive.org/download/encyclopaediabri02chisrich/encyclopaediabri02chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabri02chisrich","page_count":null},{"id":"britannica-11-v9","volume_number":"9","title":"Edwardes to Evangelical Association","year":1910,"source_url":"https://archive.org/details/encyclopaediabrit09chisrich","text_source_url":"https://archive.org/download/encyclopaediabrit09chisrich/encyclopaediabrit09chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabrit09chisrich","page_count":null},{"id":"britannica-11-v26","volume_number":"26","title":"Submarine Mines to Tom-Tom","year":1911,"source_url":"https://archive.org/details/encyclopaediabri26chisrich","text_source_url":"https://archive.org/download/encyclopaediabri26chisrich/encyclopaediabri26chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabri26chisrich","page_count":null},{"id":"britannica-11-v27","volume_number":"27","title":"Tonality to Vesuvius","year":1911,"source_url":"https://archive.org/details/encyclopaediabri27chisrich","text_source_url":"https://ia903207.us.archive.org/15/items/encyclopaediabri27chisrich/encyclopaediabri27chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabri27chisrich","page_count":null}]}}