| 释义 |
tetract, a. and n. Zool.|ˈtɛtrækt|
[f. tetra- + Gr. ἀκτ-ίς, ἀκτῑν- ray.]
a. adj. Having four rays or branches; quadriradiate.
b. n. A four-rayed sponge-spicule. So teˈtractinal a., teˈtractine a. and n., teˈtractinose a.
1886Proc. Zool. Soc. 21 Dec. 581 The chief spicules are tetract. 1887Sollas in Encycl. Brit. XXII. 416 (Fig. 12) d. calthrops (tetraxon tetractine). 1888― in Challenger Rep. XXV. p. lix, Tetractine.—When all four actines of a tetraxon are present it is..a tetractine, but as the full designation of this required to distinguish it from a tetractinose triaxon is tetractine tetraxon, we shall substitute for it the equivalent ‘calthrops’. 1891Cent. Dict., Tetractinal. |