EXPLANATION OF THE PLATES AND WOOD-CUTS. 



sents the inferior or ventral aspect of the animal ; in consequence of weathering, 



the external surface is gone, leaving an internal view of the disk and arms : p. 174. 



Fig. 6. Represents the external surface of the dorsal aspect of an arm of the same 



species, found by Lord Cole, and in his possession. 

 Fig. 6*. Three magnified segments of the same. 



N.B. The arms in the specimen, figure 5, are truncated, but there is no doubt 

 that in this, as well as in the other species, the arms were continued to a 

 great length, till they terminated in a very fine point. 



PLATE XIIL 



Description of the Plate accompanying Mr. Mantell's memoir on the Fossil Bones 

 of Birds, discovered in the Strata of Tilgate Forest : p. 175. 



Fig. 1. a. The anterior; and Jig. I. b. the posterior aspect of the lower extremity 

 of a left tarso-metatarsal bone of a bird. At o is seen the elliptical rough sur- 

 face denoting the place of attachment for the posterior or opposable toe ; and 

 it is situated at such a distance above the other toes as to prove that the bone 

 belonged to a wader, and not to an insessorial or a raptorial species. The dotted 

 outline represents a restoration of the inferior extremity of the bone, which is 

 wanting in the fossil ; probably, as Mr. Owen has suggested, from the bird having 

 been young, and the epiphysis not anchylosed. 



X Fig. 1. b. Marks the longitudinal ridges for the attachment of the aponeurotic 

 thecae, which tie down the tendons as they glide along the metatarsus to the toes. 



Fig. 2. Posterior view of the left tarso-metatarsal bone of a heron {Ardea cinerea) for 

 comparison with the fossil : o marks the place of attachment of the opposable toe. 



Fig. 3. The proximal extremity of a bone which was found vvith^^. 1. in the same 

 block of sandstone, and is so similar to the latter, both in colour, surface, and sub- 

 stance as to appear like the other extremity of the same bone. Mr. Owen con- 

 siders it to be the proximal end of a tibia of a bird. 



Fig. 4. The distal extremity of a tarso-metatarsal bone, and the bones of the toes of 

 a heron, to illustrate the nature of the fossil specimens. 



Fig. 5. a. A fragment of a bird's bone imbedded in sandstone, showing a longitudinal 

 groove. Fig. 5. b. represents a section of one extremity. 



Fig. 6. The tarso-metatarsal bone of a bird imbedded in Tilgate grit. This specimen 

 was carefully examined by Baron Cuvier, who confirmed the opinion of the author 

 of its belonging to some species oi' GrallcE. 



WOOD-CUTS 



Explanatory of Mr. Griffith's memoir on Syenite Veins in Mica Slate and Chalk, at 

 Goodland Cliff and Torr Eskert, county of Antrim : p. 179 to 185. 



No. 1. Section exhibiting the geological structure of the country from Fair Head 

 to East Torr : p. 179. 



Nos. 2.3. Syenite veins passing through mica slate in Goodland cliff, south of Murlough 



