96 
SELACHII. 
Copodus planus (Davis). 
1862. Lahodus planus (Agassiz MS.), Morris & Roberts, Quart. Journ. 
. Greol. Soc. vol. xviii. p. 101 (name only). 
1883. Lahodus planus, J. W. Davis, Trans. Roy. Dublin Soc. [2] vol. i. 
p. 470, pi. lviii. figs. 12-14. 
Type. Detached teeth; British Museum. 
Teeth mostly broader than long, though sometimes of the reverse 
proportions; crown comparatively flat; the posterior border more 
or less strongly convex in the middle, and the anterior border straight, 
with gently rounded lateral angles, and with a slight tendency to 
median excavation. Anteriorly, the tooth is somewhat narrower 
than behind; and the postero-lateral angles of the root are much 
produced backwards. The unabraded coronal surface is slightly 
rugose, and there is rarely any trace of a transverse suture ; when 
present, this is faintly marked and almost median, 
This diagnosis is founded upon the specimens in the collection, 
but it is not improbable that a small narrow portion of tooth was 
originally connected with the posterior margin of the examples thus 
described. 
Form. <Sf Log. Lower Carboniferous Limestone: Armagh, Ireland. 
P. 2590-2. Type specimens. Enniskillen Coll. 
P. 2593. Twenty-four examples, some much broken and abraded. 
Enniskillen Coll. 
49618. Small imperfect tooth, doubtfully associated with this 
species; Upper Carboniferous Limestone, Richmond, 
Yorkshire. There is a suture, as shown in No. P. 2592 
(Davis, pi. lviii. fig. 14), but the tooth is relatively broader 
and more arched antero-posteriorly. Purchased , 1878. 
49620. A smaller tooth, without suture; Richmond. 
Purchased , 1878. 
Copodus oblongus (Davis). 
1862. Mylax batoides (Agassiz MS.), Morris & Roberts, Quart. Journ. 
Geol. Soc. vol. xviii. p. 101 (name only). 
1883. Rhymodus oblongus, J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 473, pi. lviii. fig. 18. 
1883. Mylax batoides , J. W. Davis, tom. cit. p. 479, pi. lviii. figs. 25, 26. 
Type. Detached tooth ; British Museum. 
Teeth much broader than long; crown comparatively flat, the 
coronal surface only slightly raised in the middle; a posterior portion 
