344 



THE WONDERS OF GEOLOGY. Lect. IV. 



were first discovered in the chalk near Lewes, and are 

 figured in PI. xlii. of my Fossils of the South Downs. 

 Their reptilian character led me to consider them as 

 belonging to a saurian, until I obtained a considerable 

 portion of the cranium, jaws with teeth, the bone that 

 articulates the lower jaw with the skull, and several bicon- 

 cave vertebra, imbedded in a block of chalk, and belonging 

 to the same individual.* 



35. Fossil Salmon. {Lign. 72. fig. 1.) — Of the cycloid 

 order, or fishes with scales of a cycloid or circular form 

 and smooth margins, and composed of plates of horn or bone 

 without enamel, there are two or three species belonging 

 to the Salmon family, which occur in the lower chalk near 

 Lewes. These ichthyolites are exceedingly beautiful, and 

 generally have the body uncompressed, and as round and 

 perfect as when the fishes were alive. The entire cranium, 

 opercula, branchial rays, and fins, are preserved in some 

 examples. From the close affinity of these fishes to the 

 Smelt ( Osmerus), they have been named Osmeroides. In 

 one specimen I succeeded in clearing away the chalk, so 

 as to expose the entire fish, which lies six inches in relief, 

 being attached by the back to the block of stone ; the mouth 

 is open, and the opercula, or gill-covers, and the branchial 

 arches are expanded ; the pectoral, dorsal, and ventral fins 

 are in their natural position. f 



Even to those whose curiosity has not previously been 

 awakened by the Wonders of Geology, the examination of 

 these petrified inhabitants of the ancient chalk ocean can- 



* This fine specimen is now in the British Museum, with other 

 remains of the Hypsodon. 



A splendid specimen of jaws and premaxillary bones, with nume- 

 rous teeth, that differ from the Hypsodon Lewesiensis in being slightly 

 curved, is in the choice collection of Toulmin Smith, Esq. of Highgatc. 

 Two species of Hypsodon have been identified in the London clay. 



t Medals of Creation, vol. ii. p. 663. 



