SEMIONOTIDiE. 
133 
though allowance must be made for the fact that this sometimes 
deepens as the individual becomes aged. On the whole, the most 
satisfactory classification of the species represented in the Collection 
appears to be as follows :— 
I. Scales smooth on flanks. 
(а) Marginal teeth bicuspid. 
Ornament very coarse, often rugae ; scales 
finely serrated. 
Variety with more closely pectinated 
scales . 
Ornament coarse, few or no rugae ; scales 
not serrated. 
Small feebly ornamented variety of the 
same. 
« 
Ornament fine and sparse; scales not 
serrated ... 
(б) Marginal teeth unicuspid. 
Ornament coarse, sometimes rugae; scales 
serrated . 
More elongated species, with similar 
ornament but more slender teeth; 
scales not serrated.. 
Still more elongated species, similarly 
ornamented; flank-scales scarcely 
deeper than broad, not serrated.... 
II. Scales all tuberculated. 
Trunk about as deep as long, four-and-a- 
half times as deep as the caudal pedicle; 
teeth bicuspid ; scales serrated. 
Equally deep trunk with more slender 
caudal pedicle. 
politus (p. 133). 
radiatus (p. 137). 
orbis (p. 137). 
dorsalis (p. 138) 
colei (p. 140). 
punctatus (p. 142). 
pholidotus (p. 145). 
ccelatus (p. 147). 
granulatus (p. 148). 
magnevillei (p. 151). 
Dapedius politus, Leach. 
1822. Dapedium politum, Leach, Trans. Geol. Soc. [2] vol. i. p. 45, 
pi. vi. figs. 1-4. 
1832. Dapedium politum, L. Agassiz, Neues Jahrb. p. 148. 
1835-36. Dapedius politus, L. Agassiz, Poiss. Foss. vol. ii.pt, i. p. 185, 
pi. xxv. fig. 1. 
1835-44. Tetragonolepis confluens, L. Agassiz, ibid. p. 199, pi. xxiii. a. 
fig. 1. [Head ; British Museum.] 
1835- 43. Tetragonolepis speciosus, L. Agassiz, ibid. p. 199, pi. xxiii. b. 
[Nearly complete fish; British Museum.] 
1836- 44. Tetragonolepis leiosomus, L. Agassiz, ibid. p. 202, pi. xxiii. a. 
fig. 3. [Immature fish ; British Museum.] 
1852. Dapedius politus, F. A. Quenstedt, Handb. Petrefakt. p. 202. 
1854. Dapedius politus, J. Morris, Catal. Brit. Foss. p. 324. 
