. An introduction to the osteology of the mammalia . (Sorex). In RJiyncJwcyon it is broadin front, narrow posteriorly, strongly keeled below, and with two horn-like processes projectingoutwards and forwards between the attachment of theclavicles and the first pair of ribs. The mesosternum is usually narrow, as in the Carnivora,but in the Hedgehog, where it consists of three segments,it is broad and flat posteriorly, and to the last segment three VII. INSECT1VORA. 95 ribs are attached. In this genus the xiphisternum is rudi-mentary, whereas in the Shrews it is long and ends in a
. An introduction to the osteology of the mammalia . (Sorex). In RJiyncJwcyon it is broadin front, narrow posteriorly, strongly keeled below, and with two horn-like processes projectingoutwards and forwards between the attachment of theclavicles and the first pair of ribs. The mesosternum is usually narrow, as in the Carnivora,but in the Hedgehog, where it consists of three segments,it is broad and flat posteriorly, and to the last segment three VII. INSECT1VORA. 95 ribs are attached. In this genus the xiphisternum is rudi-mentary, whereas in the Shrews it is long and ends in a flatexpanded cartilage. The Mole (Talpa) and its nearest allies have a remark-ably developed presternum, which is as long as the wholeof the mesosternum (Fig. 34). It is strongly keeled below,except at the front part, which is much thickened. On its JT-. FIG. 34.—Sternum and sternal ribs of the Common Mole {Talpa europcea) with theclavicles (cl) and humeri (//). Nat. size. superior or inner surface it is grooved in the middle it gives off a pair of wing-like processes, behindwhich the first ribs are attached. It is distinctly separatedfrom the mesosternum, which consists of five segments ofnearly equal width. The xiphisternum has a broad ovalcartilaginous expansion posteriorly. 96 THE STERNUM. [CHAP. As the clavicle is supported at the anterior extremity ofthe elongated presternum, it is widely separated from thefirst rib, and the anterior extremities are brought into suchclose juxtaposition with the head that the animal appears tohave no neck. In the CHIROPTERA, the sternum presents a considerablegeneral resemblance to that of Man. The presternum islarge, trilobate in front, and strongly keeled. The meso-sternum is likewise frequently strongly keeled (Pteropus,Cynonycteris), but this keel is separated from that of th
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbones, bookyear1885
