On the Fossil Fishes of the Carboniferous Inmestone Series of Great Britain. 345 
Ctenacanthus crenulatus, Agass., MS. 
(Pl. XLV., fig. 6.) 
Ctenacanthus crenulatus—L. Agassiz, 1833. ‘Rech. Poiss. Foss.,” Vol. IIL. p. 177. 
53 5 J. E. Portlock, 1843. ‘Geol. Report, Londonderry, &e.,” p. 461. 
es 5 C. G. Giebel, 1848. “ Fauna der Vorwelt,” Vol. I., pt. 3. p. 309. 
5 % H. G. Bronn, 1848. ‘‘ Nomencl. Palzont.,” p. 355. 
he 3 x 1849. ‘ Enumerator Paleont.,” p. 649. 
FP 45 J. Morris, 1854. “Catalogue Brit. Foss.,” p. 323. 
55 i. F. J. Pictet. 1854. ‘ Traité de Paléont.,” Vol. IL., p. 290. 
Pr crenatus— IF. M’Coy, 1855. ‘ Brit. Paleeoz. Foss.,” p. 624, 3, I., fig. 31. 
crenulatus—Morris and Roberts, 1862. “ Quart. Jour. Geol. Soc.,” Vol. X VITL., p. 100. 
This specimen, which was then a part of the collection of Admiral Jones, it.p., served 
as the type of this species, was named but not described by Prof. Agassiz. The 
following is the description in the “ Paleozoic Fossils” :—Fin-spine, gradually taper- 
ing, moderately compressed, sides rather flattened, converging to a narrow, rounded, 
anterior face; each side with about ten or eleven, nearly equal, regular, rounded 
ridges, parted by sulci, about their own width apart, (at six lines wide there are five 
ridges in two lines) each ridge with a row of small transverse tubercles, strongly 
crenating the sides, down which they extend obliquely; those of each side usually 
opposite, but sometimes alternate, generally leaving the middle of each ridge smooth, 
but occasionally in some spots the small tubercles from each side ofa ridge meet on 
the middle, forming transversely rhomboidal tubercles, attenuated at the lateral 
extremities ; five lateral tubercles in the space of one line. The posterior cavity is 
rather large. 
“The length of this species is unknown, but it is probably at least four inches. 
The species is easily recognised by the regular ridges being crenulated, or milled, 
like the edge of a coin, by the small elongate tubercles, projecting at right angles 
from the sides of the ridge, and usually not encroaching on its centre.” —(M‘Coy.) 
During a recent visit to Cambridge, I was unable to find the specimen which was 
the type of this genus. It may and in all probability was, described from the 
private collection of Admiral Jones, and afterwards consigned to some other col- 
lection ; perhaps lost. 
Locality andformation: Mountain Limestone, Armagh. 
Ee coll. Woodwardian Museum, Cambridge 
Ctenacanthus rectus, Agass. MS. 
(Pl. XLV., fig. 5.) 
Onchus rectus—L. Agassiz, 1833. ‘Rech. sur les Poiss. Foss.,” Vol. III., p. 177. 
” » J. E. Portlock, 1843. ‘Geol. Report, Londonderry, &c.,” p. 461. 
6 ss C. G. Giebel, 1848. “Fauna der Vorwelt,” Vol. L, pt. 3, p. 302, 
x - H. G. Bronn, 1848. ‘‘Nomencl. Paleont.,” p. 843. 
” ” ¥ 1849, ‘ Enumerator Paleont.,” p. 652. 
” » J. Morris, 1854, ‘Catal. Brit. Foss.,” p. 334. 
» ¥ F. J. Pictet, 1854. “Traité de Paléont.,” Vol. II., p. 284. 
re) > Morris and Roberts, 1862. “ Quart. Journ. Geol. Soc.,” Vol. X VIII, p. 101 
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