§ 29. • FISHES OF THE WEALDEX. 409 



Finely striated tricuspid teeth, and others of a trans- 

 versely elongated shape, with a sharp elevated central cusp 

 and several small lateral ones, are the next in frequency. 

 These belong to fishes termed Hybodonts, allied to the 

 sharks, from which they did not materially differ in their 

 habits and economy. They possessed two dorsal spines or 

 rays, and remains of these appendages are occasionally met 

 with in the Tilgate grit and Hastings sandstone.* 



I have found in the Tilgate grit a few small oblong teeth, 

 with the surface of the crown covered by fine radiating 

 striae ; these are referable to another genus of squaloid 

 fishes (Acrodus-\\ related to the Port-Jackson shark. 



Small palatine bones, having a median row of flat trans- 

 versely arched dental plates, with two rows of hemispherical 

 obtuse teeth on the sides, are occasionally found in the quar- 

 ries around Tilgate Forest, Horsham, and Hastings. These 

 belong to fishes of the genus Pycnodas, so named from the 

 thickness of their teeth, which are constructed for crushing 

 hard substances. I have not observed any other determin- 

 able parts of these fishes. I 



Two very small fishes, belonging to the genus Leptolepis, 

 and two others equally minute, which are supposed to indi- 

 cate new generic characters, were discovered by 3Ir. Brodie, 

 in the strata containing insects, near Dinton, in the Yale of 

 Wardour.§ 



29. Eeptiles of the TTealdex. — It will doubtless 

 surprise the reader to learn that the whole of the enormous 

 bones and teeth before us, are those of reptiles, || and that 



* Medals of Creation, vol. ii. p. 607, 621. Fossils of Tilgate Forest, 

 Fl.X.fgU; Pl.XY.^.2. 



+ Medals of Creation, vol. ii. p. 614. J Ibid. p. 641. 



§ History of Fossil Insects, PI. I. Jigs. 1, 2, 3, 4 ; p. 15. 



|| This Lecture was illustrated by seyeral hundred specimens of 

 bones and teeth of reptiles from the TTealden ; many of such magni- 

 tude, that the assemblage resembled an accumulation of the disseyered 

 skeletons of gigantic elephants or mastodons. 



