PLATE III. 
DEVONIAN CRUSTACEA. 
Order —MEROSTOMATA. 
Sub- Order —EuRYPTERIDA. 
Fic. 
1. A metastoma or post-oral plate of Pferygotus anglicus, Ag., figured of the natural 
size, from the Devonian of Forfarshire. See page 39. 
2. Antepenultimate body-segment (corresponding in position to the segment marked a 
in fig. 1, Plate I); the upper surface is here represented of the natural size. 
From the Devonian of Forfarshire. See page 42. 
The original specimens are preserved in the British Museum. 
