. Bulletin. Natural history. 38 PEABODY MUSEUM BULLETIN 23 membrane that closed off the perilymphatic sac from the exterior (see Bahl, 1937, p. 140). Within the fenestra near its ventral corner is a tiny foramen marking the exit of the ninth newe. A rounded crest from the ventral edge of the paroccipital process continues ventroanteriorly to form the posteroventral border of the internal auditory meatus. It then descends vertically behind the fenestra rotunda, forming the posterior boundary of a thin superficial tongue of bone firmly sutured below to the posterolateral corner of the basal tube
. Bulletin. Natural history. 38 PEABODY MUSEUM BULLETIN 23 membrane that closed off the perilymphatic sac from the exterior (see Bahl, 1937, p. 140). Within the fenestra near its ventral corner is a tiny foramen marking the exit of the ninth newe. A rounded crest from the ventral edge of the paroccipital process continues ventroanteriorly to form the posteroventral border of the internal auditory meatus. It then descends vertically behind the fenestra rotunda, forming the posterior boundary of a thin superficial tongue of bone firmly sutured below to the posterolateral corner of the basal tuber of the basioccipital. Beneath and behind this crest and paralleling its dorsal margin are two lenticular foramina, separated from each other by a thin sheet of bone. The larger dorsal foramen (jugular foramen) transmitted the vagus and accessory nerves, the posterior cerebral branch of the internal jugular vein, and the occipital branch of the internal carotid artery to the lateral sur- face of the braincase. The smaller ventral foramen (condylar foramen) trans- mitted the hypoglossal nerve to the exterior (see Bahl, 1937, p. 139). In Clidastes these two foramina are located on the lateral face of the braincase, though in Varanus the above-described crest is greatly enlarged and the single composite foramen has been shifted around to the occipital face. The internal surface of the opisthotic-exoccipital is longitudinally concave, the cartilaginous siUures bounding it ventrally, anteriorly, and dorsally meeting at nearly right angles. The jugular foramen, which enclosed the roots of the tenth and eleventh nerves, is large and crescentic, and extends anteroventrally across the anterior half of the medial wall. The foramen for the ninth nerve is situated midway between the ventral end of the jugular foramen and the opis- thotic-prootic suture. This foramen opens externally into the floor of the perilym- phatic sac, meeting it at an angle of about 60° in the center of the brainc
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