68 
WOODWARD : SHARKS OF THE CRETACEOUS PERIOD. 
size in pi. II., fig. 8. The specimen agrees precisely in specific charac- 
ters with the other teeth already known, and its rugose coronal sur- 
face is in a fine state of preservation. 
Explanation of Plates. 
Plate I. 
1. Hybodus basanus, Egerton ; portion of skeleton of trunk, lateral 
aspect, one-half natural size. Wealden ; Sussex Coast, b. 
basal cartilage of dorsal fin ; d\ d± dorsal fin-spines ; n.s. 
neural arches and spines ; not. position of notochord ; r. 
radial cartilages. [Brit. Mus. No. P. 6357.] 
Plate II. 
1. Hybodus basanus, Egerton ; portion of endoskeleton of trunk, 
lateral aspect, two-thirds natural size. Wealden ; Sussex 
Coast, h.s. haemal arches and spines ; n.s. neural arches and 
spines ; not. portion of notochord. [Brit. Mus. No. P. 6358.] 
2. Synechodus (?) sp. dorsal fin-spine, natural size. Gault ; Folkes- 
tone. [Brit. Mus. No. P. 6501.] 
3. Synechodus illingworthi (Dixon) ; tooth, coronal (a) and inner 
(b) aspects, natural size. Chalk ; Sussex. [Brit. Mus. No. 
P. 2148.] 
4. Ditto ; tooth, outer aspect, natural size. Chalk ; Southeram, 
Sussex. [Brit. Mus. No. P. 5879.] 
5. Ditto ; tooth, coronal {a) and inner (b) aspects, natural size. 
Lower Chalk; Dover. [Brit. Mus. No. 37161.] 
6. Ditto ; tooth, coronal (a) and outer (b) aspects, natural size. 
Lower Chalk ; Guildford. [Brit. Mus. No. 49858.] 
la. d. Ditto ; group of six associated teeth, natural size. Chalk, 
England. [Brit. Mus. No. 45311.] 
8. Cestracion rugosus (Agassiz) ; tooth, coronal aspect, twice 
natural size. Lower Chalk ; Warlingham, Croydon. [Brit. 
Mus. No. P. 6489.] 
