| 释义 |
plesiaster Zool.|pliːsɪˈæstə(r)|
[f. plesio- + aster.]
In sponges, A form of spicule with a very short straight axis: see quot.
1888Sollas in Challenger Rep. XXV. p. lxiii, The plesiasters are always much larger when fully grown than the metasters,..and the metasters are larger than the spirasters; the three forms present a perfect gradational series. |