Knight. — On the Tcetlo of the Leiodon. 359 



rocks of Kansas. Yon will not be surprised to find that the fossil remains in 

 the Museum wea^e fiist ticketed as " il/osasaw?'. " 



Those who have read Mantell's " Wonders of Geology" will recall to mind 

 that Mons. Iloffman discovered the remains of the Mosasaur in the quarries 

 of St. Peter's Mount, in the suburbs of Maestficht ; how he was despoiled of 

 his specimen by the greedy canon of the cathedral ; how, when the 

 armies of the French Kepublic advanced to the gates of Maestricht and 

 the town was bombarded, the troops were not allowed to play on that part of 

 the city in which the celebrated fossil was known to be contained ; and ho^, 

 when the city was taken, the canon had to give up his ill-gotten prize, which 

 was immediately transmitted to the Jardin des Plantes at Paris, " where," 

 says Mantell, "it still forms one of the most striking objects in that 

 magnificent collection." We may regai'd with pride and exultation the 

 I'emains of the Leiodon in our Museum — a trophy of geological research, not a 

 spoil of war ! 



The enormous jaw-bone of the Mosasaurus hoffmanni measured 4^ feet 

 long ; ours, of the Leiodon, would be less than that. I shall, in this brief 

 paper, confine my remarks principally to the examination of the teeth, this 

 being the work I have undertaken as a supplement to the paper by 

 Dr. Hector.* 



It is observed by Owen that the value of dental characters is enhanced by 

 the facility with which they may be rendered available to the palaeontologist 

 in the determination of the nature and ^fiinities of extinct species, of whose 

 organization the teeth are not unfrequently the sole remains. I am not, 

 therefore, disposed to undervalue the importance of the subsidiary work I have 

 been engaged in. Mantell, by comjDaring the fossil teeth with those of recent 

 Lacertse, was able satisfactorily to place gigantic fossil remains of Tilgate Forest 

 among the extinct species of the Pleurodont section of Iguanians. Again, 

 among the Saui'ian reptiles, Owen remarks that hitherto in investigating the 

 internal structure of the teeth of the crocodile, Plesiosaur, Myalosaur, Monitor, 

 and more recent Lacertians, he had found the dentine body of the tooth to 

 consist of calcygerous tubes radiating direct from the pulp cavity at right 

 angles to the external surface of the tooth ; but, in the Lahyrvnthodon, he 

 found the most singularly complicated convolutions of the dentine. Through 

 the kindness of the Hon. Walter Mantell, T am able this evening to 

 ofier you for microscopic inspection a valuable section of the tooth of the 

 Luh. jaegeri. I could not show you a more interesting proof of the value of 

 dental characters. I have here, also, a section of the human tooth, in which 

 you will be able to trace the fine calcygerous tiibes which form the minute 

 structure of the teeth of all Vertebrates, and which, by their uninterrupted 



* See Art. LIl. 



