516 On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 
Genus.—Petalorhynchus, Agass., MSS. 
Teeth, medium size, arranged in five or six horizontal rows of at least 
three teeth each, probably five or seven. Central primary teeth beak-shaped, 
lateral ones less pointed. Apex of crown constitutes a sharp cutting surface. 
Crown, anteriorly convex, with a median ridge extending from the point downwards 
to the base ; posteriorly it is concave and spatulate ; a serics of four or five sigmoidal 
imbricating plicee extend along both surfaces of the tooth, dividing the crown from 
the base ; posterior coronal surface larger than anterior. Base, tapering, osseous, 
very long and undivided. 
(Teeth, small; crown compressed, thin, concavo-convex petal-shaped, relatively 
higher and narrower than in Petalodus ; imbricating folds on posterior face forming 
a short, transverse band, not extending to the lateral angles of the crown ; root long, 
undivided.”—Newberry and Worthen.) 
Petalorhynchus psittacinus, Agass., MSS. 
(Pl. LXI., figs. 12, 18, 14, 15, 16, 16a, 16D.). 
Chomatodus ,accuminatus /—L,. Agassiz, 1833. ‘Rech. sur les Poiss. Foss.,” Vol. II1., p. 108. 
(partim). 
Petalcdus psittacinus— L. Agassiz, 1840. ‘Rech. sur les Poiss. Foss.,” Vol. ITT., pp.174. 
and 584. 
- sagittatus, -s 1840. ‘Rech. sur les Poiss. Foss.,” Vol. III., pp.174 
and 384. 
8 55 J. KE. Portlock, 1843. “Geol. Report on Londonderry, ” p. 461. 
a psittacinus, 5 1843. ” » p- 461. 
5 5 C. G. Giebel, 1848. ‘ Fauna der Vorwelt,” Vol. I., pt. 3, p. 345. 
‘ sagittatus, on 1848. * 3 5) Vol. I., pt. 3, p. 345. 
- 55 H. G. Bronn, 1848. ‘Nomencl. Paleont.,” p. 949. 
53 psittacinus, es 1848. 06 5 p. 949. 
ms $5 5 1849. “Enumerator Paleont,” p. 646. 
. sagittatus, ee 1849. . 9 p- 646. 
3 a J. Morris, 1854. “Cat. Brit. Foss.,” p. 337. 
i psittacinus, 5 1854. ~ % db BBM 
9p % K. J. Pictet, 1854. <“Traité de Paléont.,” Vol. II., p. 272. 
5 sagittatus, es 1854. SP 5 Wolk Mb, a BIA 
» psittacinus, F. M‘Coy, 1855. “Brit. Paleeoz. Foss.,” p. 636, pl. 31, fig. 4. 
5 sagittatus, 1855, i, - » p- 636, pl. 31, figs. 2, 3. 
Petalorhynchus psittacinus—L. Agassiz, 1859. Enniskillen Coli., MSS.” 
9 5 Morris and Roberts, 1862. “Quart. Journ. Geol. Soc.,” Vol. XVIITL, 
p- 101. 
Petalodus sagittatus— 1862. “Quart. Journ, Geol. Soc.,” Vol. XVIII, 
p- 101, 
