﻿ICHXHYODORTTLITES. 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. Palaeoz. Foss. p. 625, 



pi. iii. i. fig. 32. 

 (?) 1878. Ctenacanthus heterogyrus, L. G. de Koninck, Fanne Calc. 



Carb. Belg. pt. i. p. G6, 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, fy Log. Lower Carboniferous Limestone : Armagh, and 

 (?) Tournai, Belgium. 



P. 2526-7. Two specimens, much worn at the distal extremity, 

 figured by J. W. Davi3, 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. 



P. 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 chibius, 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. 



Type. Bristol Museum. 



Form. <$f 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. 



