Assertion: eurypterid | /r/AtLocation | seam
Facets:
value: with the crustacea
type: OTHER
Source sentences:
text: Owing to the fact that British geologists seldom state the exact horizon at which fossils are collected, and of course this is often difficult to do when the strata stand on end and break off in slabs from which collections are made, it is impossible to say whether the eurypterid occurred in a seam with the crustacea while the undoubted marine forms occurred in other seams, as is found so often to be the case.