PETAL0D0NTID2E. 
57 
Polyrhizodus magmas, McCoy \ 
1843. Petalodus radicans, L. Agassiz, Poiss. Foss. yol. iii. pp. 174, 384 
(name only). 
1848. Polyrhizodus magnus, F. McCoy, Ann. & Mag. Nat. Hist. [2] 
vol. ii. p. 126. 
1855. Polyrhizodus magnus, F. McCoy, Brit. Palaeoz. Foss. p. 641, 
pi. 3 k. figs. 6-8. 
1883. Polyrhizodus radicans, J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 500, pi. lx. figs. 7, 8. 
1883. Polyrhizodus constrictus , J. W. Davis, tom . cit. p. 506, pi. lx. 
. fig- 15. 
Type. Detached tooth. 
Crown of teeth moderately high, with the base-line curved both 
in front and behind. u Rootlets ” six to eight in number, each 
generally divided again into two. 
Form. Sf Loc. Lower Carboniferous Limestone : Armagh. 
P. 2983-4. Specimens figured by J. W. Davis, loc. cit. 
Enniskillen Coll. 
P. 2965. Twenty-three specimens. Enniskillen Coll. 
P. 2978. Seven specimens ; Tynan, Armagh. Enniskillen Coll. 
P. 1467. Four small teeth, approaching P. sinuosus. Egerton Coll. 
P. 1487 b. Two imperfect large teeth. Egerton Coll. 
P. 2977. Type specimen of P. constrictus. This is a fragment of 
a tooth similar to the last. Enniskillen Coll . 
Polyrhizodus colei*, Davis. 
1883. Polyrhizodus colei, J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 502, pi. lx. figs. 9, 10. 
1884. Polyrhizodus colei, J. W. Davis, Quart. Journ. Geol. Soc. vol. xl. 
p. 622, pi. xxvii. fig. 13. 
Type . Detached tooth ; British Museum. 
Crown of tooth relatively high, with much-curved base-line, con¬ 
siderably overhanging the root in front. “ Rootlets ” only incom¬ 
pletely subdivided. 
Form. Loc. Lower Carboniferous Limestone : Armagh. Upper 
Carboniferous Limestone (Yoredale Rocks): Yorkshire (J. W. Davis). 
1 The tooth figured by Portlock (Geol. Londonderry, pi. xiv. fig. 9) under 
the name of Petalodus rectus , Agass., is considered to be a young example of 
this species by Morris and Roberts, Quart. Journ. Geol. 8oc. vol. xviii p. 102. 
