132 
ICHTHYODORrilTES. 
Physonemus gemmatus : Drepanacanthus gemma tus, Newberry & 
Worthen, Pal. Illinois, vol. ii. (1866), p. 123, pi. xiii. 
fig. 1.^-Keokuk Limestone ; Iowa. 
Physonemus giganteus : Xy sir acanthus giganteus , W. Waagen, 
Salt-Eange Possils (Palaeonfc. Indica, ser. 13), vol. i. 
880), p. 76, pi. vii. fig. 2.—Productus-Limestone; 
f . ^U ^dSalt Eange, Punjab, India. 
Physonemus gigas , 17ewberry & Worthen, op. cif. vol. iv. (1870), 
p. 373, pi. ii. fig. 1.— Burlington Limestone, Illinois. 
Physonemus JconincJci : Xystracanthus JconincJci , M. Lohest, Ann. 
Soc. Geol. Belg. vol. xi. (1883), p. 322, pi. v. figs. 2, 3.—- 
Lower Carboniferous (Ampelite); Belgium. 
Physonemus mirahilis: Xystracanthus mirabilis, St. John & Wor¬ 
then, Pal. Illinois, vol. vi. p. 458, pi. xx. fig. 1.—Coal- 
Measures; Illinois. 
Physonemus parvulus, St. John & Worthen, op. cit. vol. vi. p. 453, 
pi. xviii. figs. 11, 12.—Keokuk Limestone ; Missouri and 
Illinois. 
Physonemus proclivus, St. John & Worthen, op. cit. vol. vi, p. 451, 
pi. xviii. figs. 1, 2.—Kinderhook Limestone; Illinois. 
Physonemus reversus : Drepanacanthus reversus, St. John & Wor¬ 
then, op. cit. vol. vi. p. 456, pi. xix. figs. 5, 6, and vol. vii. 
p. 253, pi. xxiv. fig. 5.—Upper St. Louis Limestone ; 
Illinois and Missouri. 
Physonemus steilatus , J. S. Newberry, Palseoz. Pishes N. America 
(Mon. U.S. Geol. Surv. no. xvi. 1889), p. 200, pi. xxi. 
fig. 12.—St. Louis Limestone ; Greencastle, Indiana. 
[Columbia College, New \ T ork.] 
Two fragments of spines, doubtfully of this genus, from^tie 4^ro- 
ductus-Limestone of the Salt Eange, Punjab, are named Xystra¬ 
canthus gracilis , W. Waagen (tom. cit. 1879, p. 19, pi. i. figs. 2, 5), 
and X. major, W. Waagen (ibid. p. 19, pi. ii. fig. 9). 
The so-called Physonemus subteres , from the Lower Carboniferous 
Limestone of Armagh, named by Agassiz (Poiss. Loss. vol. iii. 1843, 
p. 176), and described by P. M‘Coy (Brit. Palaeoz. Poss. 1855, 
p. 638, pi. iii. i. fig. 30) and J. W. Davis (Trans. Eoy. Dublin Soc. 
[2] vol. i. 1883, p. 368, pi. xlvii. fig. 12), does not appear to belong 
to this genus ; and a very doubtful fossil from the Carboniferous 
Limestone of Moscow is named Drepanacanthus pectinifer, H. Traut- 
schold, Nouv. Mem. Soc. Imp. Nat. Moscou, vol. xiii. (1874), p. 297, 
pi. xsviii. fig. 10. 
The fragments of spines, from the Lower Carboniferous of the 
United States, named Batacantlius , St. John & Worthen (op. cit. 
