Huxley, Anat

Vert., p. 95. Abdominal reflex, a superficial reflex consisting of a contraction in the abdominal muscles when the skin over the abdomen in the mammary line is stimulated.-Ab Abdominal dermal ribs are developed in some species [of Dinosaur i a], if not in all. Huxley , Anat. Vert., p. 227. Abdominal ring, in an at.: (a) Internal , an oval open verse muscle of the abdomen), about midway between the superior iliac spine and the pubic spine, and half an inch above Poupart's ligament. (b) External , a similar oblong opening in the fascia of the obliquus extern us abdominis (external oblique muscle of the abdomen), further down and nearer the mid-line of the body. These rings are respectively the inlet and outlet of the inguinal canal. Also called inguinal rings . - Abdominal scutella, in herpet . , the short, wide, imbricated scales which lie along the belly of a serpent from chin to anus. - Abdominal segments, in entom ., etc., the individual somites or rings of which the abdomen of an insect, a crustacean, etc., is or may be composed. Abdominal vertebræ, in ichth ., all the vertebræ behind the head which have ribs or riblike proce es arching over the visceral cavity. Abdominal viscera, those organs, collectively considered, which are situated in the abdomen, being especially those of the digestive system. See abdomen , 1.