. Elementary text-book of zoology [electronic resource]. Zoology. 47$ CHORDATA. secretes the shell. They have no distinction into Fallopian tube, uterus and vagina, and they open separately into the urogenital sinus 3. Cloaca.—The urogenital canal and the alimentary canal have a common passage called the cloaca which opens by a single aperture to the exterior, the cloacal aperture (hence Monotremata). 4. Skeleton.—Shoulder-girdle has complete pre-cora coids, coracoids and episternum. The scapula is bent for- ward, and the spine is at the anterior border, not down the middle. Fig. 295.—Ventral
. Elementary text-book of zoology [electronic resource]. Zoology. 47$ CHORDATA. secretes the shell. They have no distinction into Fallopian tube, uterus and vagina, and they open separately into the urogenital sinus 3. Cloaca.—The urogenital canal and the alimentary canal have a common passage called the cloaca which opens by a single aperture to the exterior, the cloacal aperture (hence Monotremata). 4. Skeleton.—Shoulder-girdle has complete pre-cora coids, coracoids and episternum. The scapula is bent for- ward, and the spine is at the anterior border, not down the middle. Fig. 295.—Ventral View of Pectoral Girdle and Fore-Limb of Ornithorhynchus. {Ad. naf.). Other skeletal peculiarities must be noted. The pelvis bears a pair of epi-pubic bones similar to those of the Meta- t/ieria, and at least in Echidfia the acetabulum is incompletely ossified. The cervical ribs are incompletely fused on to the cervical vertebrae, and the dorso-lumbar vertebrae have no epiphyses, or only traces of them. The cranial bones anky- lose early obliterating all sutures,'"^ and the rami of the mandible are free. There is an ent-epicondylar foramen in the humerus. * The young Ornithorhynchits is said to possess p7'e- and post-frontal 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 Masterman, Arthur Thomas; Parsons, John Herbert, Sir, 1868-1957, donor; S. H. Lazarus (Firm); University College, London. Library Services. Edinburgh : E. & S. Livingstone
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1901
