Article: Some additions to our knowledge of antiarchs

The author has in his collection some uncrushed antiarch material which is very beautifully preserved. This has enabled him to determine the shape of Bothriolepis with real certainty, and to describe the muscle insertions on the helmet process, and thus interpret their function. The material also shows the opercular plate, and its relation to the branchial cavity, thus suggesting the probable nature of the gill arches, and enabling them to be compared with those of other groups.