. A manual of zoology. xii PHYLUM CHORDATA 443 of the trunk, usually ten in number, are immovably united together. Each of the neural spines, from the second to the ninth inclusively, is expanded into a flat plate, and the row of neural plates (Fig. 266, V), thus formed constitutes the median portion of the carapace. The ribs are likewise immovable ; a short distance from its origin each passes into a large bony costal plate (C), and the series of costal plates uniting by their edges form a large part of the cara- pace on either side of the row of neural plates. The cara- pace is made up of th
. A manual of zoology. xii PHYLUM CHORDATA 443 of the trunk, usually ten in number, are immovably united together. Each of the neural spines, from the second to the ninth inclusively, is expanded into a flat plate, and the row of neural plates (Fig. 266, V), thus formed constitutes the median portion of the carapace. The ribs are likewise immovable ; a short distance from its origin each passes into a large bony costal plate (C), and the series of costal plates uniting by their edges form a large part of the cara- pace on either side of the row of neural plates. The cara- pace is made up of the neural and costal plates supplemented by a row of marginal plates (Figs. 265 and 266, M) running along the edge, and nuchal (Nu) and pygal (Py) plates. Fig. 266.—Chelone midas. Transverse section of skeleton. C, costal plate; C, centrum; M, marginal plate; P, lateral element of plastron; R, rib; I', expanded neural plate. (After Huxley.) situated respectively in front of and behind the row of neural plates. The bony elements of the plastron of the Chelonia are an anterior and median plate and six pairs of plates — the six pairs probably being of similar nature to the abdominal ribs of the Crocodilia. The sternum in the Lacertilia is a plate of cartilage with a bifid posterior continuation. In the Ophidia and Chelonia it is absent. In the Crocodilia it is a broad plate with a posterior continuation or hyposternum, extending backwards as far as the 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 Parker, T. Jeffery (Thomas Jeffery), 1850-1897; Haswell, William A. (William Aitcheson), 1854-1925. New York, The Macmillan Company; London, Macmillan & Co. ,Ltd.
Size: 2373px × 1053px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1900
