334 
SKLACmi. 
25858. Typo specimens, figured, of the natural size, in PI. XIII. 
figs. 11, 12; Upper Greensand, Maidstone. Dixon Coll. 
39217. Two teeth, one relatively narrow and tapering at each extre- 
mity ; Maidstone. Bowerhmik Coll. 
P. 2125. Two teeth named “ Strophod^is sulcatus,” in Agassiz’s hand- 
writing ; Maidstone. Egerton Coll. 
P. 2664. Imperfect abraded tooth ; Maidstone. Ennislcillen Coll. 
Cestracion canaliculatusy Egerton. 
1850. Cesiracion eanaliculatm, Sir P. Egerton, in Dixon’s Foss. Suss, 
p. 8C6, pi. xxxii.* fig. 8. 
1850. Acrodus cretacMK, F. Dixon, op. cit. p. 364, pi. xxx. fig. 13. 
1853. Cestracion canaliculatus, Sir P. Egerton, Quart. Joum. Geol. Soc. 
Tol. ix. p. 281. 
1872. Drepanephorus canaliculatus, SirP. Egerton, Figs. & Descrips. 
Brit. Organic llemains (Mem. Geol. Surv.), dec. xiii. pi. ix. 
1883. Cestracion canaliculatus, C. Ilasse, Neues Jahrb, vol. ii. p. 66. 
- 1887. Drepanephorus canaliculatus, A. S. Woodward, Geol. Mag. [3] 
vol. iv. p. 105. 
1888. Drepanephorus canaliculatus, A. S. Woodward, Proc. Geol. Assoc, 
vol. X. p. 200. 
Type. Associated teeth. 
Anterior dorsal fin-spine placed approximately over the twenty- 
fifth vertebra. Extremities of the principal lateral teeth rounded, 
and the longitudinal coronal keel in these raised mesially into a low 
rounded eminence ; root pierced by a large oblique perforation. 
Form. ^ Loc. Senonian : S.E. England. 
49735. The right pterj-go-quadrate and mandibular cartilages, with 
the anterior extremity of the left mandibular, preserved in 
the two halves of a small block of chalk ; Uiqier Chalk, 
Guildford, Surrey. Though much crushed and broken, 
the ptcrygo-quadrate has the appearance of being notably 
longer than the mandibular. A few of the anterior teeth 
are displayed, and two are shown, of three times the 
natural size, from the posterior and anterior aspect respec- 
tively, in PI. XI. figs. 24, 25 ; each has one j)air of broad 
lateral denticles. Some of the principal lateral teeth of 
the upper jaw also occur in position. Those of the largest 
scries (PI. XI. fig. 26) measure 0'007 in length, and those 
of tho series immediately behind (PI. XI. fig. 26) 0’005 ; 
