Tapetum

(ta-pe'-turn). I. The layer forming the roof of the posterior and middle cornua of the lateral ventricles of the brain; it is composed of fibers from the corpus callosum. 2. In biology, a term applied to the lining membrane of the pollen-sac. T. cellulosum. See T. fibrosum. T. fibrosum, a shining structure in the choroid of the eye. It takes the place of the T. cellulosum of the carnivora, the iridescent portion of the choroid in these animals. T. lucidum, the brilliant, greenish, reflecting layer or membrana versicolor of the eyes of many of the lower animals. T. nigrum, the pigmentary layer of the retina. See Pigmentary Layer. T. ventriculi, a bundle of white fibers of the brain uniting the cortex of the frontal with that of the occipital lobe, Tap hi phobia (tafe-fo' -be-ah). Morbid fear of burial alive, 'aphrenchyma (tafreng' '-kim-ak). In biology, a vegetal ti ue composed, of pitted ducts. Also called Bothrenchyma and Pitted ue. 'api no cephalic (tap-in-o-sef -al'-ik). Affected with tapinocephaly. 'apinocephalus (tap-in-o-sef ' -al-us). A subject of tapinocephaly. 'apinocephaly (tap-in-o-sef /-al-e). Flatne of the top of the cranium, 'api no cran i us (tap-in-o-kra'-ne-us). Li auer"s term for a skull in which the greatest height of the cranial cavity is from 74.5 to 1 82.5 per cent, of its greatest length, apinopisthius. Li auer's term for a skull in which the angle formed between the radius fix us and the line joining the occipital point and the punctum alas vomer is 1= between 24. 50 and 35°.