444 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. V. 



large, and placed close to each other on each side the median line ; the 

 margins of the jaws are fringed with brush-teeth, and the jaws marked 

 with granulated longitudinal ridges. These dental characters resemble 

 those of two living genera of fishes, the Thyrsites and Lepidopus. The 

 specimens are from Lewes, and were collected in 1820. * 



SAURODON. Wall-case C. (No. 23.) There are several detached, 

 lanceolate, laterally compressed teeth, and two or three specimens in 

 which teeth of the same character are affixed to a portion of the jaw, in 

 the front of this division of Case 6'. The latter instructive specimens 

 were in the cabinet of the late Mr. Dixon ; the former are from my col- 

 lection. 2 These fossils belong to an extinct genus of fishes, which 

 resembled the Sphyrcena, or Barracuda Pike, in the form of the teeth 

 and length of the jaws. The teeth on the palatine bones are barbed, and 

 finely serrated. 3 The teeth of these fishes were first discovered in the 

 Cretaceous Greensand of New Jersey, in the United States. 4 



HYPSODON (H. Lewesiensis). Wall-case C. (No. 24.) 5 The ichthyo- 

 lites thus named are also from the Lewes chalk, and were among my 

 earliest discoveries. They consist of the teeth and jaws, vertebrae, and 

 some of the cranial bones, of a very large predaceous fish, whose long, 

 conical, unequal teeth, remind us of the sauroids of the ganoid order. 

 The three pieces of chalk containing portions of jaws with teeth, verte- 

 brse, &c. are fragments of a large block, which was broken up by the 

 quarrymen before the animal remains were observed. I collected the 

 least injured pieces, and removed the chalk so as to expose the bones 

 now apparent 6 This genus is now referred to the family of Scombero- 

 esocids, of Miiller. 



Of the freshwater fishes the Cyprinoids or Carps, there are fossil 

 species of Tinea or Tench (T.furcata, and T.leptosoma) from (Eningen; 

 and of the Leuciscus or Luce, there is a very large fossil species (L. 

 Hartmanni) from the tertiary strata of Steinheim, in Wirtemberg, and a 

 small fish of the same genus (L. papyraceus), from the paper-coal of 

 Bayreuth. 



The fossil Esocids or Pikes, are in Cases Nos. 24 to 27, and com'prise 

 some beautiful examples of Esox lepidotus from (Eningen. Of an extinct 

 fresh-water genus named Sphenolepis, allied to the Pikes, there is a 

 specimen of a very large species with robust vertebrae, and long striated 

 scales, (S. squammoseus,) from Aix ; and the S.Cuvierifrom Montmartre. 



The Ichthyolites of the Halecoids or Herring family, comprising the 

 Clupeae and Salmonidae, are placed in Cases No. 25 and 26. Among 

 the former is the Clupea Scheuchzeri, from the slate of Glaris. 



1 Figured in " Fossils of the South Downs," under the name of Esox 

 Lewesiemis, Tab. XL1. " Geology of the South-East of England," p. 140. 



2 Figured in " Fossils of the South Downs," Tab. XXXIII. 



3 See "Medals of Creation," p. 666, Lign. 136, fig. 3. 

 * See " Medals of Creation," p. 669. 



5 Tab. XLII. "Fossils of the South Downs," represents a vertebra, 

 teeth, and bones of a fish of this genus. 



6 These specimens are figured in M. Agassiz's " Recherches sur les 

 Poissons Fossiles." 



