22 



DESCRIPTION OF THE PLATES. 



lars. Fig. 2. Upper and lower molars, 

 right side, of the nine-banded Armadillo 

 (Tatusia Peba). Fig. 3. Ditto of the 

 Weasel-headed Armadillo (Dasypus 6- 

 cinctus). F. Cuvier. Fig. 4. Longitudinal 

 section of the tooth of Dasypus 6-cinc- 

 tus). Magnified 300 linear diameters ; a, 

 osteo-dentine ; b, b, hard dentine ; c, 

 cement. Original. 



PLATE 86.. 



Fig. 1. — Portion of a molar tooth of the 

 gigantic extinct Armadillo (Glyplodon 

 clavipes). Fig. 2. Grinding surface of 

 ditto. Fig. 3. Part of magnified section 

 of ditto ; a, osteo-dentine ; b, b, hard 

 dentine ; c, cement. Fig. 4. Transverse 

 section of upper molar of Toxodon platen- 

 sis ; \ nat. size. Fig. 5. Ditto of lower 

 molar of Toxodon. ( The enamel is erro- 

 neously drawn as extended over the whole 

 concave folded side of the tooth). Ori- 

 ginal. 



PLATE 87. 



Fig. 1 . Reduced view of base of skull, with 

 the hidden rudimental tusk, and the base 

 of the long tusk of the male Narwhal. 

 (The mirror not having been used, this 

 tusk is figured in the right, instead of the 

 left intermaxillary). Fig. 2. Base of 

 skull of female Narwhal, with both the 

 rudimental tusks exposed. Fig. 3. Eden- 

 tulous lower jaw of the Narwhal. Fig, 

 4. Section of large tusk of the male. 

 Home. 



PLATE 87 a. 



Fig. 1 . Rudimental teeth in the alveolar 

 groove of the upper jaw of the fetal Ba- 

 Icenoptera Boops. Fig. 2 to 6. Teeth 

 from the same of the natural size. Esch- 



richt. Fig. 7. Lower jaw and teeth of 

 the Gangetic Dolphin (Platanista gange- 

 iica) ; a and b, detached teeth, nat. size. 

 Home. 



PLATE 88. 



Fig. 1. End of the upper jaw of a young 

 Hyperoodon bidens, shewingthe two teeth. 

 Fig. 2. Part of the lower jaw of a Dol- 

 phin (Delphinus Delphis) ; with the roots 

 of the teeth exposed. Original. 



PLATE 89. 



Fig. 1. Reduced view of the lower jaw and 

 teeth of a Cachalot or Sperm-whale (Phy- 

 seter macrocephalus). Fig. 2. Section of 

 a tooth of ditto, ^ nat. size ; a, cement ; 

 b, dentine ; c, osteo-dentine. Fig. 3. 

 One of the concealed teeth of the upper 

 jaw; nat. size. 4. Fore part of its pointed 

 end. Original. 



PLATE 89 A. 



Fig. 1 . — Part of longitudinal section of the 

 teeth of a Cachalot, magnified 230 linear 

 diameters. Fig. 2. A peripheral portion 

 of ditto, magnified 500 linear diameters ; 

 a, b, dentine ; c, cement. Original. 



PLATE 90. 



Fig. 1. — Inside view of left ramus, lower 

 jaw, of Diprotodon australis, ^th nat. 

 size ; i, outline of incisive tusk ; m, 1 to 

 5, molar teeth. Fig. 2. Outline of trans- 

 verse section of crown of incisor, shewing 

 partial covering of enamel. Fig. 3. Crown 

 of penultimate molar ; m, 4, nat. size. 

 Fig. 4. Inside view of left ramus, lower 

 jaw of Nototherium inerme, jth nat. size ; 

 m, 1 to 4 ; outlines of molar teeth. Fig. 



5. Crown of penultimate molar of Tapi- 

 rus amtricanus, nat. size. Original. Fig. 



6. Upper and lower jaw of Mastodon an- 



