144 
ICHTHYODORTJLITES. 
It still remains uncertain whether the small spine from the 
Middle Coal-Measures of Tingley, Yorkshire, described under the 
name of G. denticulatus , Davis l , is not the unworn spine of the 
young of G. formosus, as described by R. H. Traquair 2 . The 
following specimen is of the same form, but only one posterior 
series of denticles is displayed 
P. 2289. Yearly complete spine 0*15 in length, unornamented for 
a distance of 0*045 from the apex ; Coal-Measures, Goran, 
near Glasgow. Presented by George Griffiths, Esq., 1882. 
The small spine from the Calciferous Sandstone Series of Burdie- 
house, near Edinburgh, figured by S. Hibbert, Trans. Roy. Soc. 
Edinb. vol. xiii. (1835), pi. xi. fig. 1, and assigned to Gyracanthus 
formosus by Agassiz (tom. cit. p. 17), is of doubtful species. The 
following are of a similar type :— 
P. 6238. Basal fragment of a large spine ; Burdiehouse. 
Purchased , 1847. 
P. 2243. Broken small spine; Burdiehouse. Egerton Coll. 
P. 3146, Less imperfect small spine ; BurdiehQuse. 
Enniskillen Coll. 
The following species have also been described, but there are no 
examples in the Collection :— 
Gyracanthus alleni , J. S. Newberry, Rep. Geol. Surv. Ohio, vol. i. 
pt. ii. (1873), p. 331, pi. xxxvii. fig. 3.—Waverly Group 
(Cuyahoga Shale) ; Ohio. [Columbia College, Yew York.] 
Gyracanthus compressus, J. S. Yewberry, ibid. p. 330, pi. xxxvii. 
figs. 1, 2. — Waverly Group; Ohio and (?) Indiana. 
[Columbia College, Yew York.] 
Gyracanthus duplicatus , J. W. Dawson, Acadian Geol. 2nd edit. 
(1868), p. 210, woodc. fig. 55 ; J. S. Yewberry, Palaeoz. 
Eishes Y. America (Mon. U. S. Geol. Surv. no. xvi. 1889), 
p. 124.—Coal-Measures ; Yova Scotia. [Redpath Museum, 
Montreal.] 
Gyracanthus incurvus , R. H. Traquair, Geol. Mag. [3] vol. vii. 
(1890), p. 21.—Lower Devonian ; Campbellton, P. Q., 
Canada. [Edinburgh Museum.] 
1 J. W. Davis, Ann. Mag. Nat. Hist. [5] vol. vi. (1880), p. 373, woodcut. 
2 Ann. Mag. Nat, Hist. [5] vol. xiii. (1884), p. 40 
