| Answer | Crossword Clue |
|---|---|
| SHELL | Slight, hollow structure. |
| DIP | Slight hollow. |
| DENT | Slight hollow |
| SLIM | Slight in structure |
| asthenic | (of a physical type) having a slight build or slender body structure |
| mouths | An opening or entrance to a structure that is hollow, concave, or almost completely enclosed |
| gastrulae | An embryo at the stage following the blastula, when it is a hollow cup-shaped structure having three layers of cells |
| endocast | the fossilized outline of a hollow organic structure, as a skull or a mollusk shell, formed when mud or sediment consolidated within the structure and the structure itself disintegrated or dissolved |
