PETALODONTID iE. 
51 
Ctenoptychius dentatus (Owen). 
1843. Ctenoptychius dentatus, L. Agassiz, Poiss. Foss. vol. iii. pp. 173, 
383 (name only). 
1843. Ctenoptychius macrodus , L. Agassiz, tom. eit. pp. 173,*383 (name 
only). 
1840-45. Petalodus dentatus, R. Owen, Odontography, vol. i. p. 62. 
1843. Ctenoptychius macrodus , J. E. Portlock, Rep. Geol. Londond. 
p. 467, pi. xiv. fig. 7 (inaccurate figure). 
1862. Harpacodus dentatus , J. Morris & G. E. Roberts, Quart. Journ. 
Geol. Soc. vol. xviii. p. 100 (name only). 
1881. Harpacodus dentatus , J. W. Davis, Ann. & Mag. Nat. Hist. [5] 
vol. viii. p. 426. 
1883. Harpacodus dentatus, J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 514, pi. lxi. fig. 10. 
Type. Detached tooth ; (?) British Museum 1 . 
Margin of dental crown not acuminate, divided into few (about 
5-7) relatively large, smooth, pointed denticulations; anterior base¬ 
line of crown gently curved. In the principal teeth the median 
denticulation is scarcely larger than those immediately adjoining. 
Root markedly tumid below, truncate. 
Form. Sf Loc. Lower Carboniferous Limestone : Armagh. 
P. 3008. Tooth described and figured by J. W. Davis, loc. cit. 
Enniskillen Coll. 
Enniskillen Coll. 
P. 3009. Twenty-two teeth. 
P. 1441. Six teeth. 
28926, 28736. Ten teeth. 
Egerton Coll. 
Purchased, 1854. 
Ctenoptychius lobatns (Etheridge). 
1875. Petalodus P lobatus , R. Etheridge, jun., Geol. Mag. [2] vol. ii. 
p. 244, pi. viii. figs. 5, 6. 
1883. Ctenopetalus crenatus, J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 513, pi. lxi. fig. 9 (broken tooth). 
1884. Ctenopetalus crenatus , J. W. Davis, Quart. Journ. Geol. Soc, 
vol. xl. p. 623, pi. xxvii. fig. 18. 
Type. Detached tooth; coll. James Bennie. 
Margin of dental crown acuminate. Denticulations in principal 
teeth about 9-13 in number, smooth and pointed, but appearing as 
if crenulated when worn; those of the unsvmmetrical lateral teeth 
more numerous and obtuse. Anterior base-line of crown sharply 
1 An unmarked specimen in Admiral Jones’s collection, either in the Museum 
or in the possession of the Geological Society. 
E 2 
