DESCEiniON OF PLATES. 421 



XXVII. A DESCRIPTION OF THE PLATES IN 

 THE FAUNA ANTIQUA SIVALENSIS. 



(Compiled by the Editoe, from Notes and Memoranda by H. Ealconee, M.D.) 



[This description has been mainly compiled from the following 

 sources : — 1. Memoranda in Dr. Falconer's note-books and papers ; 

 2. References to certain of the figures in his published memoirs on 

 Elephant, Mastodon, &c. ; 3. Eeferences to other figures in his 

 correspondence with scientific friends ; and 4. Labels in his handwriting 

 on the specimens figured which are now in the British Museum. 

 Although the figures are drawn to scale, the actual measiirements have, 

 as far as practicable, been introduced into the description of each 

 figure. It has been thought that by their means, the value of the 

 descriptions would be increased to those who have not an opportu- 

 nity of consulting the Plates, and that even to those who possess 

 the Plates the comparison of specimens would be facilitated. The 

 measiu:ements are given in English inches, and in tenths of an inch. 

 The letters B.M. indicate that the specimen referred to is in the 

 British Museum. — Ed.] 



Plates I., II., and III. are intended to represent, by careftil copies of 

 nature, the modifications in structure and form exhibited by the molar 

 teeth of the Prohoscidea. They show in vertical sections a series of 

 gradations, commencing -with Dinothermn and Mastodon Ohioticus at one 

 extremity, and running through the other species to Elephas jn-imigenms, 

 in which the greatest deviation from the ordinary form of a grinding 

 tooth is met with. 



Plate I. 



Fig. 1. — Elephas primigenius, or the true Mammoth : longitudinal 

 and vertical section of last upper molar, left side, from an English 

 specimen found near Kingsland, and formerly in the Museum of the 

 Geological Society. Shows the ' ridge formula ' and the form and 

 relative proportions of the alternate layers of ivory. The section 

 closely resembles that of the corresponding tooth of the Indian 

 Elephant, but the ivory segnaents are even thinner, more vertical, and 

 more approximated. The disposition of the plates presents the ex- 

 treme degree of ' pectination ' seen in the molars of any known 

 species of elephant. — B.M. (Eeproduced in Plate V. fig. 3.) 



Length, 11 in. No. of plates, 21. Depth of enamel at tenth plate, 6-2 in. 

 Length of space to 10 plates, 4 J in. 



Fig. 2 a. — Elephas Indicus. Vertical section of an upper penulti- 

 mate molar of the existing Indian Elephant. It is composed of 

 seventeen ridges, with a reduced talon' splent behind, the anterior 



