﻿150 1CHTI1YODORULITE3. 



(1S37), p. 7, pi. i. figs. 3-5. — Old Red Sandstone ; Brom- 

 yard, Herefordshire. [? Cephalaspidian cornua.] 



Byssacanthus gosseleti, C. Barrois, Ann. Soc. Geol. du Nord, vol. ii. 

 (1875), p. 200, and Comptes Rendus Assoc. Franc,. 1874, 

 p. 381.— Upper Devonian ; Couvin, Ardennes. 



Byssacantlms Icevis, L. Agassiz, Poiss. Foss. V. G. R. (1845), 

 pp. Ill, 117, pi. xxxiii. fig. 15: Byssacanthus dilatatus, 

 E. von Eichwald, Leth. Rossica, vol. i. (1860), p. 1598 : 

 Byssacantlms (Onchus) dilatatus, E. von Eichwald, Bull. 

 Soc. Imp. Nat. Moscou, vol. xix. (1846), p. 288, pi. x. 

 figs. 2, 3. — Devonian ; St. Petersburg. 



A spine from the Upper Silurian of the Baltic Provinces, ex- 

 hibiting considerable resemblance to Byssacanthus, is named Rabda- 

 canthus truncatus, 0. H. Pander, Foss. Fische Silur. Syst. russ.- 

 balt. Gouvernements (1856), p. 69, pi. vi. fig. 26. 



The following genera also seem to belong to this group of Ich- 

 thyodorulites : — 



Cyrtacanthus, J. S. Newberry (Rep. Geol. Surv. Ohio, vol. i. pt. ii. 

 1873, p. 306), with the single species, C. dentatus, Newberry, ibid. 

 p. 307, pi. xxix. fig. 5. [Doubtfully assigned to Erismacanihus 

 (" Cladacanthus ") by J. S. Newberry, Palaeoz. Fishes N. America 

 (Mon. U.S. Geol. Surv. no. xvi. 1889), p. 29.]— Corniferous Lime- 

 stone (Lower Devonian); Delaware, Ohio. [Columbia College, 

 New York.] 



Euacanthus, H. Trautschold (Bull. Soc. Imp. Nat. Moscou, 1883, 

 pt. ii. p. 171), with the single species, E. margaritatus, Traut- 

 schold, ibid. p. 172, pi. v. figs. 7-13. — Carboniferous Limestone ; 

 Moscow. [Trautschold Collection, Breslau.] 



Harpacanthus, R. H. Traquair (Ann. Mag. Nat. Hist. [5] 

 vol. xviii. 1886, p. 493), with the single species, H. fimbriatus, 

 Traquair (ibid. p. 493, woodcut), previously named Tristychius 

 fimbriatus, T. Stock (Ann. Mag. Nat. Hist. [5] vol. xii. 1883, p. 177, 

 pi. vii. fig. 1). — Middle Carboniferous Limestone ; Gilmerton, 

 near Edinburgh. [Edinburgh Museum.] Also St. Louis Limestone 

 (Lower Carboniferous) ; Alton, Illinois l , 



Ostracacanthus, J. "W. Davis (Rep. Brit. Assoc. 1879, p. 343, and 

 Quart. Journ. Geol. Soc. vol. xxxvi. 1880, p. 64), with the single 

 species, O. dilatatus, Davis, ibid. 1879, p. 343, and ibid. 1880, 

 p. 64, woodcut. — Cannel Coal (Middle Coal-Measures); Tingley, 

 Yorkshire. [Collection of J. W. Davis, Esq., Halifax.] 



1 J. S. Newberry, Palaeoz. Fishes N. America (Mon. U.S. Geol. Surv. no. xti. 

 1889), p. 203, pi. xxi. fig. 11. 



