201 



From these details the following changes are inferred : 



1st, A surface of dry land, consisting of gravel derived from the 

 neighbouring rocks, either while the district was submarine, or during 

 the rise of the strata, or by subsequent denudation, or by these causes 

 united, 



2ndly, The surface was covered with a forest of birch, oak, and fir. 



3rdly, The forest was destroyed, or it decayed, and a peat bog was 

 formed. 



4thly, A rush of sea buried the bog beneath a mass of loam and 

 gravel, containing fragments of existing marine shells and granite 

 boulders. 



In conclusion, the author draws attention to the natural sections 

 on both sides of the Severn, west of Shrewsbury, about one mile above 

 the Welsh Bridge, in one of which he obtained, after much search, a 

 few fragments of shells ; and he begs geologists in general, both in 

 England and Ireland, to institute a patient examination of the super- 

 ficial gravel of iheir neighbourhood for fragments of shells, however, 

 comminuted. 



A paper was also read, entitled, " Description of some Fossil Crus- 

 tacea and Radiata 5" by William John Broderip, Esq., F.G.S. F.R.S., 

 &c. 



Lord Cole and Sir Philip Egerton having placed in the author's 

 hands some fossils which they had lately found in the lias at Lyme 

 Regis, a detailed account is given, in the memoir, of those which he 

 considers to be new. 



Crustacea. 

 The first specimen described consists of the anterior parts of a ma- 

 crourous Decapod, between Palinurus and the Shrimp family, but of a 

 comparatively gigantic race ; and its organization being considered by 

 the author to be sui generis, he has assigned to the fossil the name of 

 Coleia antiqua, with the following generic characters : 



" Antenn<s. Base of mesial anl^nnsi (antenna: internd) not extending 

 beyond the anterior spine of the thorax ; each antenna terminated 

 by two annular setse. External antennse provided with a large and 

 rude scale, and having a spine on the exterior of the penultimate 

 joint: the terminal setae large, but the length undetermined. 



" Eyes pedunculated, directed outwards, approaching in their situa- 

 tion and form to those of Palinurus. 



"Feet. First pair long, slender; the cubit {cubitus) with small spines 

 or serratures on the internal margin, and terminated externally by 

 three strong spines. 



" Hand (inanus) elongated, slender ; digits slightly incurved, fili- 

 form, unarmed, pointed. 



" Thorax thin (divided transversely by furrows indicating the dif- 

 ferent regions), tuberculate, spinous at the sides, and with three deep 

 emarginations anteriorly, the middle one the largest; each of the four 

 anterior angles produced into a strong spine." 



The collection contained the remainsof other macrourous Decapods. 

 One of these specimens consisted of a fragment of the post-abdomen, 



