PLATE V. 
DEVONIAN CRUSTACEA. 
Order—MEROSTOMATA. 
Sub-Order—EuRyYPTERIDA. 
Fic. 
1-4 Represent the detached penultimate joint of the swimming-foot or maxillipede 
(prognathite, Huxley) of Pterygotus anglicus, Agassiz, from the Devonian of For- 
farshire. Figured of the natural size. (See pages 38 and 39.) 
1 Represents the outline of the joint as seen from the under surface. (See Plate VIII, 
figenls 63) 
2. Side view of same, exhibiting the upper surface and the ridge (7); p, proximal 
articular surface; d, distal extremity, to which the oval terminal palette was 
articulated. 
3. View (foreshortened) of joint as seen from the proximal end (y), showing the under 
side and the ridge (7) upon the dorsal surface, somewhat bent over to one side. 
4. Section (drawn from careful measurement) of about the centre of the joint, showing 
the thickness of the internal portion. (7 represents the ridge, as in figs. 2 and 3.) 
From the Museum of James Powrie, Esq., F.G.S., of Reswallie, Forfarshire. 
