172 



OLDER PLIOCENE FORMATIONS. 

 Fi2. 155. 



[Ch. XIV. 



Astarte (Crassina, Lam.): species common to upper and lower crag. 



Astarte Omalii, Lajonkalre; Syn. A. Mpartita, Sow. Min. Con. T. 521, f. 3; a very variable 



species, most characteristic of the Coralline Crag, Suffolk. 



volutes of the torrid zone, and may, like the living Voluta Magellanica, 

 have been fitted for an extra-tropical climate. 



Fig. 156. 



Fig. 157. 



Fig. 158. 



Voluta LamterU, young 

 Individ., Cor. and Eed 

 Crag. 



Pyrula reticulata, Lam. ; 

 Coralline Crag, Eam- 

 sholt. 



Temnechimis exca'Dafus, 

 Forbes ; Temnopleui-us 

 excavatus, Wood; Cor. 

 Crag, Eamsholt. 



The occurrence of a species of Lingula at Sutton (see fig. 160) is worthy 

 of remark, as these Brachiopoda seem now confined to more equatorial 

 latitudes ; and the same may be said still more decidedly of a species of 

 Pyrula^ supposed by Mr. Wood to be identical with P. reticulata (fig. 

 15 7), now living in the Indian Ocean. A genus also of echinoderms, 

 called by Professor Forbes Temnechinus (fig. 158), is peculiar to the Red 

 and Coralline Crag of Suff'olk. The only species now living occur in the 

 Indian Ocean. Whether, therefore, we may incline to the belief that the 

 mean annual temperature was higher or lower than now, we may at least 

 infer that the climate and geographical conditions were by no means the 

 same at the period of the Suftblk Crag as those which now prevail in the 

 same region. 



One of the most interesting conclusions deduced from a careful com- 

 parison of the shells of these British Older Pliocene strata and the fauna 

 of our present seas, has been pointed out by Prof E. Forbes. It appears 

 that, during the glacial period, a period intermediate, as we have seen, 

 between that of the crag and our own time, many shells, previously estab- 

 lished in the temperate zone, retreated southwards to avoid an uncon- 

 genial chmate. The Professor has given a list of fifty shells which in- 

 habited the British seas while the Coralline and Red Crag were forming, 



