In sarcophagi

Morgan Bulkeley, Berkshire Stories, Great Barrington (MA), 2004.

It was difficult to understand how such a clear stream could feed so many fish unless they ate gravel, and that proved more fact than fancy, for a few opened stomachs revealed that the main supply of food was caddis-fly larvae, those soft little bodies that encase themselves in sarcophagi of gravel or bits of vegetation for protection.