. Elements of comparative anatomy. Anatomy, Comparative. PELVIC GIRDLE OF VERTEBRATA. 485 buluni into two divergent pieces (Fig. 269), which enclose a large opening (foramen obturatum). The anterior process is called the pubis (P), the posterior one the ischium (Js). The two bones of either side are more or less connected together along the middle line, but this connection may disappear. The pelvis of the Crocodilini. Fig. 269. View of the left side of the pelvis of Monitor. Jl Ilium. Js Ischium. P Pubis, a Hinder cud of the ilium, b Its anterior process. Fig. 270. View of the left side of the
. Elements of comparative anatomy. Anatomy, Comparative. PELVIC GIRDLE OF VERTEBRATA. 485 buluni into two divergent pieces (Fig. 269), which enclose a large opening (foramen obturatum). The anterior process is called the pubis (P), the posterior one the ischium (Js). The two bones of either side are more or less connected together along the middle line, but this connection may disappear. The pelvis of the Crocodilini. Fig. 269. View of the left side of the pelvis of Monitor. Jl Ilium. Js Ischium. P Pubis, a Hinder cud of the ilium, b Its anterior process. Fig. 270. View of the left side of the pelvis of Alligator lucius. x y Two limbs of the ischium, which unite with r s, two processes of the ilium, to enclose a foramen (o) at the base of the acetabulum. The other letters as iu Fig. 269. (Fig. 270) differs from this in many points, for a single bone (Js) is given off ventrally from the acetabulum, and is connected by means of two processes with the ilium (x y). It appears to represent an ischium only, while a bone, which takes no part in the acetabulum, but articulates with the ischium (p), and converges, like its fellow, towards the anterior wall of the abdomen, represents the pubis. The pelvis in the fossil Dinosaurii was of the same character; the ilium was distinguished by a process which was directed forwards, and of which there is an indication only in the extant Saurii and Crocodilini (b). The acetabulum was similarly incomplete, and was connected with a long ischium, which was directed obliquely back- wards and downwards, and was not united with its fellow of the opposite side. A long pubis, which also ended freely, was given off from the anterior margin of the acetabulum, and ran parallel to the ischium. This relation of parts is the same as that which characterises the Avian pelvis (Fig. 271). In them the ilium (J7) does not only extend a long way back (a a), but its anterior process is converted into a broad plate (b b). This extends along the lumbar regi
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectanatomycomparative
