PYCX0D0XTIDJ5. 
231 
A species of small or moderate size, known only by the splenial 
dentition. Teeth closely arranged ; those of the innermost series 
minute and round ; those of the principal series about twice 
as broad as long ; teeth of the inner flanking series broader than 
long and larger than those of the outermost row, which are 
rounded. 
Form. Sf Loc. Bathonian : Oxfordshire. 
P. 523. Type specimen ; Stonesfield Slate, Stonesfield. Egerton Coll. 
Microdon (?) discoides (A. S. Woodward). 
1844. Pycnodus discoides, L. Agassiz, Poiss. Foss. yoL ii. pt. ii. p. 199 
(name only). 
1890. Mesodon discoides, A. S. Woodward, Proc, Geol. Assoc. yoL xi. 
p. 300, pi. iii. fig. 32. 
Type. Imperfect vomer ; British Museum. 
A species doubtfully ascribed to Microdon , known only by the 
unique vomer recorded below. Vomerine teeth round and well 
spaced; those of the median series not much exceeding the outer 
lateral teeth in size; inner paired teeth only about half as large as 
the others. 
Form. 6f Loc. Bathonian : Oxfordshire. 
P. 524. Type specimen, described and figured loc. cit. 1890; Great 
Oolite, Little Gibraltar, near Oxford. Egerton Coll. 
I V 'Y' 
The following specimens of M&odon are not specifically deter¬ 
mined :— 
P. 7444. Vomer; Kimmeridgian, Langenberg, Hanover. 
Purchased , 1895. 
P. 3756. V omer resembling Microdon in its anterior half, but the 
inner lateral teeth not interposed between the median 
teeth in its hinder half ; Purbeckian, Swanage. 
Enniskillen Coll. 
The following species of Microdon have also been founded upon 
portions of dentition, but there are no examples in the Collection : — 
Microdon corcdli: Fycnodus coralli , H. E. Sauvage, Bull. Soc. 
Sci. Hat. Tonne, vol. xxxiii. pt. ii. (1879), p. 32, pi. ii. 
fig. 2.—Upper Corallian ; Tonnerre, Tonne, France. 
[Bight splenial; Cotteau Collection.] 
Microdon distantidens : Fycnodus clistantidens , F. J. Pictet, Bept. 
et Poiss. Foss. Jura Beuchatelois (1860), p. 67, pi. xv. 
