ICHTHYODORTTLITES. 
131 
P. 2869. Four imperfect and much abraded specimens. 
Enniskillen Coll . 
P. 2870. Much abraded smaller spine, doubtfully of this species ; 
Hook Point, Wexford. Enniskillen Coll . 
Physonemus hamatus (Agassiz). 
1837. Onchus liamaius , L. Agassiz, Poiss. Foss. vol. iii. p. 9, pi. i. 
figs. 7, 8. 
1883. Physonemus hamatus , J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 370, pi. xlvii. figs. 9, 11. 
1884. Physonemus hamatus , J. W. Davis, Quart. Journ. Geol. Soc. 
vol. xl. p. 617, pi. xxvi. fig. 6. 
Type. Bristol Museum. 
Form. Log. Lower Carboniferous Limestone : Gloucestershire. 
Dpper Carboniferous Limestone : Yorkshire. 
P. 4901. Spine of the form assigned to this species by J. W. Davis, 
loc. cit. (1884) ; Yoredale Rocks, Wensleydale, Yorkshire. 
Elorne Coll. 
The following species have also been described, hut there are no 
examples in the Collection :— 
Physonemus cicinciciformis : Xystracanthus acinaciformis, St. John 
& Worthen, Pal. Illinois, vol. vi. (1875), p. 459, pi. xx. 
fig. 2.—Coal-Measures ; Illinois. 
Physonemus anceps \ Prepanacanthus anceps, Yewberry & Wor¬ 
then, Pal. Illinois, vol. ii. (1866), p. 122, pi. xii. fig. 8: 
Xystr acanthus anceps , St. John & Worthen, op. cit. vol. vi. 
p. 458.—Coal-Measures ; Illinois. [Type of Prepanacan - 
thus.~\ 
Physonemus arcuatus : Xystracanthus arcuatus , J. Leidy, Proc. 
Acad. Yat. Sci. Philad. 1859, p. 3, and Ext. Yert. Fauna 
W. Territ. (Rep. L.S. Geol. Surv. vol. i. 1873), p. 312, 
pi. xvii. fig. 25.—Upper Coal-Measures; Kansas. [Type 
of Xystracanthus , requires new specific nameT] 
Physonemus carinatus , St. John & Worthen, op. cit. vol. vi. p. 452, 
pi. xviii. figs. 4, 5.—Kinderhook Limestone; Illinois. 
Physonemus chesterensis , St. John & Worthen, op. cit. vol. vi. 
p. 455, pi. xix. fig. 4.—Chester Limestone ; Illinois. 
Physonemus clepressus, St. John & Worthen, op. cit. vol. vi. p. 452, Xce 
pi. xviii. fig. 3.—Kinderhook Limestone ; Illinois. 
Physonemus falcatus, St. John & Worthen, op. cit. vol. vii. (1883), 
p. 252, pi. xxiv. fig. 6.—St, Louis Limestone ; Missouri. 
k 2 
Ms. 
