COCHLIODONTID^. 
213 
I860. Cochliodus amituf, F. M‘Coy, Brit. Palsooz. Foss. p. 021, pi. 3 i. 
fig. 24. 
1862. Deltoptychius acutm, Morris & Roberts, Quart. Joum. Geol. Soc. 
vol. xviii. p. 100 (name only). 
1867. Coe/tlmltis compacts, R. Owen, Geol. Mag. vol. iv. pi. iv. fig. 1. 
1883. Dcltoptychius avutue, .1. W. Davis, Tran.s. Roy. Dublin Soc. [2] 
vol. i. p. 433, pi. liii. figs. 13-17. 
1883. Deltodus e.vpamm, . 1 . W. Davis, tom. cit. p. 431, pi. liii. figs. 9, 10 
(non fig. 11). 
(?)1884. DeltoptycMus plicattis, J. W. Davis, Quart, .lourn. Geol. 
Soc. vol. xl. p. 628, pi. xxvi. figs. 13, 14. 
(?) 1886. Deltoptychius plicatux, . 1 . W. Davis, Geol. JIag. [3] vol. iii. 
p. 162. 
Type. Detached dental plates ; Woodwardian Museum, Cam- 
bridge. 
“ Upper ” dental plate expanded posteriorly towards the inner 
border ; the large coronal ridge angulated ; lateral borders raised 
into sharp ridges. “ Lower ” plate with the large median ridge 
angulated, sharply separated from the upturned postcro-lateral area. 
Form. 4' Toe. Lower Carboniferous Limestone : Armagh, Ireland, 
and Ayrshire, Scotland. Upper Carboniferous Limestone ; York- 
shire and Derbyshire. 
(i.) Sliylitly curved variety (‘^ upper jaw). 
P. 2433-35. Three dental plates described and figured by J. W. 
Davis, loc. cit. p. 4.33, pi. liii. figs. 15-17 ; Armagh. 
Ennislcillen Coll. 
P. 2448-9. Two specimens described and figured as referable to the 
upper jaw of Deltodus expansus, J. W. Davis, loc. cit. ; 
Armagh. Ennislcillen Coll. 
P. 2436. Thirty specimens ; Armagh. Enniskillen Coll. 
P. 1455. Four small abraded dental plates ; Armagh. 
Eyerton Coll. 
28725. Two similar plates ; Armagh. Purchased, 1853. 
46045. Imperfect dental plate probably of this species ; Beith, Ayr- 
shire. Presented by It. Craig, Esq., 1874. 
(ii.) Inrolled variety (? loiver jaw). 
P. 2431-2. Two dental plates descjibed and figured by J. W. Davis. 
loc. cit. p. 433, pi. liii. figs. 13, 14; Armagh. 
Enniskillen Coll. 
P. 2437. Twenty specimens; Armagh. 
Enntskillen Coll. 
