Edrioaster sentence example
- Turning to fossil Asteroidea, we find the earlier ophiurids scarcely distinguishable from the asterids, while in the alternation of the ambulacrals, which undoubtedly correspond to the flooring-plates of Edrioaster, both groups approach the Pelmatozoan type.
- No other way out for them is apparent, and it is clear that Edrioaster was not permanently and solidly fixed to the sea-floor.
- We suppose some such form as Edrioaster, which appears to have lived near the shore, to have been repeatedly overturned by waves.
- If this be correct, the only change from Edrioaster, as regards the ambulacra, was that in Palaeodiscus the covering-plates could no longer open, but closed permanently over the whole groove, while the podia issued through slits between them.
- The genital organs in both Asteroidea and Echinoidea would retain the interradial position they first assumed in Edrioaster; and in Echinoidea their primitive temporary openings to the exterior were converted into definite pores, correlated with five interradially placed plates at the aboral pole.Advertisement