adumbrellar, a. Zool.
(ˌædʌmˈbrɛlə(r))
[mod. f. L. ad to, at + umbrella, applied to the disc of Acalepha, + -ar. Cf. adactinal, adoral.]
In sea-blubbers: Pertaining to the upper surface of the velum or marginal ridge, which is turned towards the ‘umbrella’ or disc, in opposition to the abumbrellar or lower surface.
| 1881 E. R. Lankester in Jrnl. Microsc. Sc. Jan. 131 The ectoderm of the adumbrellar surface of the velum. |