ICHTHYODORULITES. 
101 
Ctenacanthus heterogyrus, M‘Coy. 
1843. Ctenacanthus heterogyrus, L. Agassiz, Poiss. Foss. vol. iii. p. 177 
(name only). 
1855. Ctenacanthus heterogyrus , F. M'Coy, Brit. Pakeoz. Foss. p. 625, 
pi. iii. i. fig. 32. 
(P) 1878. Ctenacanthus heterogyrus, L. G. de Koninck, Fanne Calc. 
Carl). Belg. pt. i. p. 66, pi. vii. fig. 3. 
1883. Ctenacanthus heterogyrus , J. W. Davis, Trans. Roy. Dublin Soc. 
[2] vol. i. p. 336, pi. xliv. figs. 1-3. 
Type. Woodwardian Museum, Cambridge. 
Form. Sf Log. Lower Carboniferous Limestone : Armagh, and 
(?) Tournai, Belgium. 
P. 2526-7. Two specimens, much worn at the distal extremity, 
figured by J. "W. Davis, Joe. cit. Enniskillen Coll. 
P. 2528, P. 2671. Seven imperfect specimens, similarly worn dis- 
tally; also a much abraded spine, probably of the same 
species. 
Enniskillen Coll. 
• jp. 2228. Spine extremely worn distally. Egerton Coll. 
28928-29. Two fragmentary spines. Purchased , 1854. 
The following is an indeterminable crushed and broken spine 
slightly smaller than most examples of C. heterogyrus :— 
P. 2530. Type specimen of Ctenacanthus dubius, J.W. Davis, loc.cit. 
p. 340, pi. xliv. fig. 7; Lower Carboniferous Limestone, 
Armagh. Enniskillen Coll. 
Ctenacanthus sulcatus (Agassiz). 
1837. Onchus sulcatus, L. Agassiz, Poiss, Foss. vol. iii. p. 8, pi. i. fig. 6. 
1883 Ctenacanthus sulcatus , J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 343, pi. xlv. fig\ 3, 
Jkri ' ses - ■ f\*AA ( S U~ 
Type. Bristol Museum. 
Form. Sf Loc. Lower Carboniferous Limestone: Gloucestershire, 
Shropshire, and (?) Armagh, Ireland. 
P. 228. Imperfect exserted portion of spine; Oreton, Shropshire. 
Weaver-Jones Coll. 
P. 2670. Smaller, more slender spine, similarly marked; Armagh. 
Enniskillen Coll. 
P. 2871. Very small spine, similarly marked and distally worn; 
Armagh. Enniskillen Coll. 
