0STE0GL0SSIDJ5. 
83 
Plethodus pentagon, A. S. Woodward. 
1899. Plethodus pentagon, A. S. Woodward, Ann. Mag. Nat. Hist. [7] 
vol. iii. p. 356, pi. xiii. figs. 5-7. 
Type. Lower dental plate ; liritish Museum. 
A smaller species, tlie lower dental plate attaining a length of 
about 0’055 with a maximum breadth of 0'04. Lower dental 
plate elongated, pentagonal in shape, widest near the pointed end, 
and the border of the truncated end slightly excavated ; grinding 
■surface slightly convex. Supposed upper dental plate quadrangular. 
No hones of this species have hitherto been identified. 
Form. £f Loc. Turonian : S.E. England. 
41716 a. Lower dental plate, being the type specimen describe 
and figured loc. cit. p. 356, pi. xiii. fig. 5 ; Lower Chalk, 
Burham, Kent. Toulmin Smith Coll. 
47947. Pointed end of lower dental plate, figured loc. cit. pi. xiii. 
fig. 6 ; Burham. Presented by the Hon. Robert 
Mar sham, 1877. 
35874. Imperfect abraded lower dental plate, the truncated end 
exhibiting a deep accidental cleft ; Lower Chalk, Dover. 
Purchased, 1861. 
P- 2693. Two fragments; Lower Chalk, Lowes. Enniskillen Coll. 
P. 5626. Supposed upper dental plate, described and figured loc. cit. 
p. 357, pi. xiii. fig. 7 ; Lower Chalk, Kent. Referred to 
Tliryptodus sp. by E. B. Loomis, Paloeontogr. vol. xlvi. 
(1900), p. 235. Harford Coll. 
49816. Portion of similar plate ; Lower Chalk, Dorking, Surrey. 
Capron Coll. 
Plethodus oblongus, Dixon. 
1850. Plethodus oblongus, F. Dixon, Geol. Sussex, p. 366, pi. xxxii.* 
fig. 4. 
1899. Plethodus oblongus, A. S. Woodward, Ann. Mag. Nat. Hist. [7] 
vol. iii. p. 357, pi. xiv. 
Type. Lower dental plate ; Brighton Museum. 
A very small species, the lower dental plate about 0'02 in length, 
elongated and irregularly ovoid in shape, the broader end gently 
rounded, the narrower end truncated; grinding surface of this 
plate slightly convex. 
A small skull in the Brighton Museum, described and figured by 
g 2 
