PYCX0D0NTIDJ3. 
205 
in Agassiz’ handwriting, described and figured in Proc. 
Geol. Assoc, vol. xi. (1890), p. 299, pi. iii. fig. 27; Stones- 
field. Enniskillen Coll. 
P. 1666. Similar splenial dentition of left side; Stonesfield. 
Egerton Coll. 
P. 3734. Four more imperfect small examples of the splenial den¬ 
tition ; Stonesfield. Enniskillen Coll. 
Mesodon bucklandi (Agassiz). 
1833-44. Py modus bucklandi, L. Agassiz, Poiss. Foss. vol. ii. pt. i. 
p. 16, pt. ii. p. 192, pi. lxxii. a. fig. 15 ( non figs. 16-22). 
1839-44. Pycnodus didymus , L. Agassiz, ibid. p. 193, pi. lxxii. a. figs. 24, 
25. [Mandibular dentition ; British Museum.] 
1839-44. Pycnodus ovalis, L. Agassiz, ibid. p. 195, pi. lxxii. a. fig. 5. 
[Vomerine dentition ; Bristol Museum.] 
1840. Pycnodus bucklandi, R. Owen, Odontogr. pi. xxxiv. fig. 2. 
1840. Pycnodus didymus , R. Owen, ibid. pi. xxxiv. fig. 3. 
1844. Pycnodus obtusus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 199 
(name only). [Vomer; British Museum.] 
1871. Pycnodus bucklandi , J. Phillips, Geol. Oxford, p. 179, woodc. 
xxxix. figs. 4, 5. 
1871. Pycnodus didymus, J. Phillips, ibid. p. 179, woodc. xxxix. fig. 6. 
1885. Mesodon bucklandi , F. Bassani, Atti Soc. Ital. Sci. Nat. 
vol. xxviii. p. 160. 
1889. Mesodon bucklandi, A. S. Woodward, Geol. Mag. [3] vol. vi. 
p. 454. 
1890. Mesodon bucklandi , A. S. Woodward, Proc. Geol. Assoc, vol. xi. 
p. 297, pi. iii. figs. 20-22. in. Us£. Uni\j. */eucR£d( 
. . ox*, h* R. Jfa.i'iru.i- iq 
Type. Vomerine dentition ;(Oxford Museum.) sv*. net. ^ ’ 
A species of large size, known only by the dentition. Teeth i<«• 
smooth, often irregular in outline, the rounded contour being fre¬ 
quently interrupted by angulations. Vomerine teeth well spaced ; 
those of the median series, except quite anteriorly, less than twice 
as broad as long, but their breadth exceeding that of the two 
lateral series; teeth of the inner lateral series much larger than 
those of the outer series, not regularly alternating; a few small 
scattered teeth also occurring irregularly between the median and 
inner lateral series. Splenial teeth well spaced, those of the 
principal series almost twice as broad as long, flanked within by a 
single row of small rounded teeth and externally by three regular 
series, of which the second only equals the innermost row in size, 
while the first is slightly larger, and the third (or outermost) much 
larger than all except the principal series. 
