Search the Dictionary

Having the limbs on, or directed toward, the neural side, as in most invertebrates; -- opposed to Ant: hæmapodous. G. Rolleston.

The deep-seated parts of the vertebrate skeleton which are relation with the nervous axis and locomation. Owen.

An embryo or certain invertebrates in the stage when the primitive band is first developed.

An elastic cartilagelike rod which is developed beneath the medullary groove in the vertebrate embryo, and constitutes the primitive axial skeleton around which the centra of the vertebræ and the posterior part of the base of the skull are developed; the chorda dorsalis. See Illust. of Ectoderm.

An oarlike swimming organ of various invertebrates. Oar cock (Zoöl), the water rail. [Prov. Eng.] -- Spoon oar, an oar having the blade so curved as to afford a better hold upon the water in rowing. -- To boat the oars, to cease rowing, and lay the oars in the boat. -- To feather the oars. See under Feather., v. t.…

nd surrounds the great foramen by which the spinal cord leaves the cranium. In the higher vertebrates it is usually composed of four bones, which become consolidated in the adult. -- Occipital point (Anat.), the point of the occiput in the mesial plane farthest from the ophryon.

Of or pertaining to the occipital bone and second vertebra, or axis.

A little eye; a minute simple eye found in many invertebrates.

ntoid process, or Odontoid peg (Anat.), the anterior process of the centrum of the second vertebra, or axis, in birds and mammals. See Axis.

A group of Mesozoic birds having the jaws armed with teeth, as in most other vertebrates. They have been divided into three orders: Odontolcæ, Odontotormæ, and Saururæ.

olfactory nerves; the olfactory cells. Olfactory organ (Anat.), an organ for smelling. In vertebrates the olfactory organs are more or less complicated sacs, situated in the front part of the head and lined with epithelium innervated by the olfactory (or first cranial) nerves, and sensitive to odoriferous particles con…

One of the single eyes forming the compound eyes of crustaceans, insects, and other invertebrates.

A metamere of the vertebrate skeleton; an osteomere; a vertebra. Owen.

The science which treats of the bones of the vertebrate skeleton.

Same as Vertebrata.

An auditory cyst or vesicle; one of the simple auditory organs of many invertebrates, containing a fluid and otoliths; also, the embryonic vesicle from which the parts of the internal ear of vertebrates are developed.

the small bones or particles of calcareous or other hard substance in the internal ear of vertebrates, and in the auditory organs of many invertebrates; an ear stone. Collectively, the otoliths are called ear sand and otoconite.

An extinct genus of huge vertebrates, probably dinosaurs, known only from four-toed tracks in Triassic sandstones.

An artifical division of vertebrates, including those that lay eggs; -opposed to Vivipara.

The sweetbread, a gland connected with the intestine of nearly all vertebrates. It is usually elongated and light-colored, and its secretion, called the pancreatic juice, is discharged, often together with the bile, into the upper part of the intestines, and is a powerful aid in digestion. See Illust. of Digestive appa…