XX1V EXPLANATIONS OF THE PLATES. 
Prare VII. —Fig. 1, Cheiracanthus microlepidotus. Fig. 2, Magni- 
fied scales. Figs. 3, 4, 5, 6, 7, 8, Vegetable impressions of the Old 
Red Sandstone. 
Puate VIII.— Fig. 1, Diplacanthus longispinus. Fig. 2, Diplacan- 
thus striatus. Fig. 3, Magnified scales of fig 1. Fig. 4, Spine of fig. 
2, slightly magnified. 
Pruatr IX.— Restoration of Coccosteus, incomplete, found in Mr. 
Miller’s Museum after his death. (Seventh Edinburgh edition, 1858.) 
Puiate X.— Restoration of Cephalaspis, from several specimens lately 
found in Forfarshire. (Seventh Edinburgh edition, 1858.) 
Pratt XI.—Fig. 1, One of the tail flaps of the gigantic Crusta- 
cean of Forfarshire. Fig. 2, Reticulated markings of Carmylie. 
Prats XII. — Parka decipiens, from a specimen in the private col- 
lection of Lord Kinnaird, at Rossie Priory. (Seventh Edinburgh edi- 
tion, 1858.) 
Prate XIII.— Fig. 1, Cephalaspis Lyellii, copied from Lyell’s El- 
ements of Geology. Fig. 2, Holoptychius Nobilissimus, copied on a 
greatly reduced scale from Murchison’s Silurian System. Fig. 3, Scale 
of Holoptychius, natural size. Fig. 4, Tooth of ditto, also natural size. 
These last drawn from specimens in the collection of Mr. Patrick Duff, 
of Elgin. 
Prate XIV.—Figure of a Holoptychius, found some time ago in 
Dura Den, Fifeshire, and now in the possession of a private collector 
in Dundee. (Seventh Edinburgh edition, 1858.) 
