from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A rooflike structure of the body, especially the dorsal part of the midbrain.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The dorsal portion of the midbrain, containing the superior colliculus and inferior colliculus
- n. The interconnected outer surface of a spore.
from The Century Dictionary and Cyclopedia
- n. Same as tectorium.
Before about 1970, most studies involved non-mammals-fish, frogs, birds-that is, species in which the tectum is the dominant structure that receives input from the eyes.
The tectum is a layered structure, with a number of layers that varies by species.
Reptiles include water snakes, Indian python Python molurus (V), banded krait Bungarus fasciatus, green rat snake Zaocys nigromarginatus, turtles (Lissemys punctatus, Trionyx gangeticus, Kachuga tectum and Hardella thurgi) and monitor lizard Varanus sp.
Dómine, non sum dignus ut intres sub tectum meum: sed tantum dic verbo, et sanábitur anima mea.
With regard to political theory, the difference between Hobbes and myself, which is the subject of your inquiry, consists in this, that I always preserve the natural right in its entirety [ego naturale jus semper sartum tectum conservo], and I hold that the sovereign power in a State has right over a subject only in proportion to the excess of its power over that of a subject.
Verres, against whom Tully so much inveighs, in winter he never was extra tectum vix extra lectum, never almost out of bed,  still wenching and drinking; so did he spend his time, and so do myriads in our days.
Calcium signals monitored from leopard frog optic tectum after the optic nerve has been selectively loaded with calcium sensitive dye
Intrinsecus sunt parietes vndíque de filtro, sed et tectum filtreum est: has domus, dum locum habitandi mutare volunt, vel dum indiuitina expeditione procedunt, ducunt secum in plaustris quasi tentoria.
Porrò de Baldakino erat tectum superius, sed alij erant panni exterius.
In 1973 (Science, Vol. 181, p. 1053) I showed that while the tectum was needed to react to moving prey, another visual area processed stationary edges, allowing frogs to dodge stationary barriers and to avoid tumbling into holes in the ground.