Geological Society of London. 239 



Mr. Prestwich then stated the localities at which these sub-clivisions 

 of the Coralline Crag are exposed, and proceeded to discuss the geo- 

 graphical distribution of the existing species in the several zones, 

 and the present range of the organic remains. He agreed in the 

 opinion that the greater number of the Mammalian remains are ex- 

 traneous fossils ; but regarded those of a whale as truly contem- 

 poraneous, and probably also the teeth of the Rhinoceros and 3Ias- 

 todon, while the bones that are more or less drilled he considered to 

 be derived. The occurrence of a large block of porphyry in the 

 basement-bed at Sutton was considered a proof that a considerable 

 degree of winter cold had been attained at that period, as it would 

 be difficult to account for its presence in that bed except by ice- 

 action ; the author also enumerated the physical conditions which 

 seem to be suggested by the mineral character and the structure of 

 the several zones, inferring, from the peculiar mixture of southern 

 forms of life with others of a more northern type, that at this early 

 period the setting-in of conditions of considerable cold had com- 

 menced. 



With the aid of Mr. Gwyn Jeffreys, the author had revised the 

 list of Mollusca from the Coralline Crag, and he gave a Table in 

 which the range of the species in space, depth, and time was given, 

 and an analysis of their synonymy by Mr. Jeffrej^s. He also dis- 

 cussed the relations of the Coralline Crag with its foreign equi- 

 valents, agreeing in the conclusion that the Crag Noir is a stage 

 older than it, while the destruction of beds of the age of some of the 

 older Crags of Belgium have furnished many of its derived fossils. 

 In conclusion the author described the distribution of sea and land 

 at the period of the deposition of the Coralline Crag, as suggested 

 by the affinities of the fossils of that deposit. 



ni. March 25th, 1868. — 1. " On some new species of Palaeozoic 

 Crustacea from the Upper Silurian rocks of Lanarkshire, etc., and 

 further Observations on the Structure of Pterygotus.'' By Henry 

 Woodward, Esq., F.G.S., F.Z.S. 



The nature of the remains which have been referred by Mr. Salter 

 to Pierygotns (but by the author to Eurypterus) punctatus was first 

 discussed by the author, who came to the conclusion that the Lanark- 

 shire specimens belong to a new s]3ecies — Eurypterus scorpioides, — 

 while the chelate antennas and the detached lip -plate from Ludlow 

 must have belonged to other species. 



Eurypterus scorpioides is the first of the new forms now described 

 by Mr. Woodward, and is represented by a specimen exhibiting an 

 almost entire individual, and certain other fragments. The punc- 

 tate ornamentation of this species may be readily distinguished from 

 the scale-like markings of Pterygotus and Slimonia. The second new 

 iorm, Eurypterus obesus, is remarkable for the great obesity of the 

 thoracic somites ; it is represented by the impression and counter- 

 part of an entire specimen. Its small size suggested to the author 

 the possibility of its being the young of some larger species. The 

 third new species, Pterygotus raniceps, is at present known only by 



