100 
IGHTHYODORCTLITES. 
Ctenacanthus denticulatus, M‘Coy. 
1848. Ctenacanthus denticulatus , F. M‘Coy, Ann. Mag. Nat. Hist. [2] 
yoI. ii. p. 116. 
1855. Ctenacanthus denticulatus , F. M‘Coy, Brit. Palseoz. Foss. p. 625 
pi. iii. k. fig. 16. 
1883. Ctenacanthus denticulatus , J. W. Davis, Trans. Boy. Dublin Soc. 
[2] vol. i. p. 338, pi. xliv. fig. 4. 
Type. Woodwardian Museum, Cambridge. 
Form. &{ Log. Lower Carboniferous Limestone: Armagh and 
Shropshire. Lower Carboniferous : Monaduff, Drumlish, N. Ireland. 
41193-94. Two imperfect small spines ; Greton, Shropshire. 
Purchased , 1868. 
42237. Fragment; Oreton. Baugh Coll. 
Ctenacanthus brevis, Agassiz. 
1837. Ctenacanthus brevis, L. Agassiz, Poiss. Foss. vol. iii. p. 11, pi. ii. 
fig. 2. 
1883. Ctenacanthus brevis , J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 337, pi. xliii. fig. 3. 
1883. Ctenacanthus limaformis, J. W. Davis, ibid. p. 339, pi. xliv. fig*. 5. 
[British Museum.] 
Type . Bristol Museum. 
Form. Sf Log. Lower Carboniferous Limestone: Bristol. 
22665. Two partially broken spines, naturally associated, the hinder 
being smaller and narrower than the foremost. 
Purchased , 1848. 
34982. Imperfect example. Purchased , 1860. 
P. 2226. Spine, and fragment labelled by Agassiz. Egerton Coll. 
P. 3111-2. Spine figured and described by J. W. Davis, tom. cit. 
p. 337, pi. xliii. fig. 3; also a fragment labelled by 
Agassiz. Enniskillen Coll. 
P. 6231. Fragmentary specimen. Purchased. 
P. 2535. Type specimen of G. limaformis, J. W. Davis, loc. cit. 
p. 339, pi. xliv. fig. 5. This is a much broken spine, and 
so far as its characters are distinguishable cannot be sepa¬ 
rated from C. brevis; the published figure is misleading. 
Enniskillen Coll. 
