50 
8ELACHII. 
Pet([lodopsis, J. W. Davis (iion W. J. Barkas), Trans. Roy. Dublin 
Soc. [2] vol. i. 1883, p. 498. 
Teeth as in Petalodus, but having the coronal margin coarsely 
denticulated. 
Ctenoptychius apicalis, Agassiz. 
1838. Ctenoptychius apicalis, L. Agassiz, Poiss. Foss. vol. iii. p. 99, 
pi. xix. fig. 1. 
1841. Ctenoptychius apicalis, E. W. Binney, Trans. Manchester Geol. 
Soc. vol. i. p. 109, pi. v. fig. 19. 
1873. Ctenoptychius apicalis, T. P. Barkas, Coal Meas. Palseont. p. 18, 
pi. i. fig. 21. 
1874. Ctenoptychius apicalis, W. J. Barkas, Monthly Rev. Dental 
Surgery, vol. ii. pp. 443, 482, figs, xiv., xv. 
1874. Petahdus apicalis, W. .T. Barkas, tom. cit. p. 638. 
1876. Ctenoptychius apicalis, J.Ward, [Proc.] f^orth Staffs. Nat. Field- 
Club, p. 218, fig. 12. 
T\jpe. Detached tooth ; British Museum. 
Teeth with coronal margin acuminate, divided into few (5-9) 
relatively largo, smooth, but pointed dcnticulations ; anterior base- 
line of the crown slightly curved. In the principal teeth the median 
denticulation is prominent and much the largest. Root markedly 
tumid helow, truncate. 
Form. ^ Loc. Coal-Measures : Lanarkshire, Scotland; Northumber- 
land, Yorkshire, Lancashire, Staffordshire, England. 
P. 496. Typo specimen ; Silverdale, Staffordshire. Egerton Coll. 
P. 3020, P. 3023. Seven teeth, variously broken and abraded; New 
Ironstone (Rag-mine), Fenton, N. Staffordshire. 
Ennishillen Coll. 
P. 1458, P. 1460-1. Six teeth ; Fenton. Egerton Coll. 
34995-7, P. 246. Four teeth ; Fenton. Purchased, 1860, 1880. 
P. 5167-8. Three portions of teeth ; Fenton. Purchased, 1885. 
46028. Crown of tooth ; Longton, N. Stafford.shire. 
Presented hy John Ward, Esq., 1874. 
P. 3022. Fine tooth ; Harecastle, N. Staffordshire. Ennishillen Coll. 
P. 1459. Tooth ; Lowmoor, Yorkshire. Egerton Coll. 
P. 3021. Three teeth ; Carluke, Lanarkshire. Ennishillen Coll. 
21423. Tooth; Carluke. Purchased, 1847. 
