42 
SELACHir. 
The following species have also been founded upon detached 
teeth, but there are no examples in the CoUoction : — 
Pefalorhi/nchus dislortus, St. John & Worthen, Pal. Illinois, vol. vi. 
(1875), p. 400, pi. xii. figs. 7, 8. — Upper St. Louis Lime- 
stone ; Illinois, Iowa, Missouri. 
FetalorJiynchus indicas, W. Waagen, Pal. Ind. ser. 13, pt. i. (1879), 
p. 17, pi. i. fig. 8. — Produotus Limestone ; Salt llange, 
India. (? Janassa.) 
Petnlorhynchus pseudosngittatus, St. John & Worthen, tom. cit. 
p. 405, pi. xii. tigs. 1-4. — -Upper St. Louis Limestone ; 
Illinois, Iowa, Missouri. 
PetalorhynoJms spatidatm, St. John & Worthen, tom. cit. p. 408, 
pi. xii. figs. 5, 6. — Upper St. Louis Limestone ; Illinois, 
Iowa. 
Petalorhynclius striaius, Newberry & Worthen, Pal. Illinois, 
■ vol. ii. (1860), p. 40, pi. ii. fig. 8. — Burlington Limestone ; 
Illinois. 
Genus PETALODUS, Owen. 
[Odontography, 1840-4.5, p. 61.] 
Syn. Chomatodus, L. Aga.ssiz (in part), Poiss. Foss. vol. iii. 1838, p. 108. 
Antliodus, Newberry & Worthen, Pid. Illinois, vol. ii. 1800, p. 33. 
Sicarius, J. Leidy, Proc. Acad. Nat. Sci. Philad. vol. vii. 1850, 
p. 414. 
Teeth much transversely elongated and compressed. The crown 
is petal-shaped, with a smooth or delicately crenulated margin. In 
the typical species the root is relatively large, though in some 
(‘^Antliodus” and “Chomatodus”) comparatively short; it is tumid 
and truncated at its lower extremity. 
Petalodus acuminatus (Agass.). 
1838. Chomatodus acuminaius, L. Agassiz, Poiss. Foss. vol. iii. p. 108, 
pi. 10. figs. 11-13. 
1840-45. Petalodus hastingsii, II. Owen, Odontogr. p. 01, pi. xxii. 
figs. 3-6. 
1843, Petalodus acuminatus, L. Agassiz, to^n. cit. pp. 174, 384. 
(?) 184.3. Petalodus hastinqsii, J. F. Portlock, Kep. Geol. Londonderry, 
p. 408, pi. xiv. fig. 10. 
18-48. Petalodus rhombus, F. McCoy, Ann. & Mag. Nat. Hist. [2] vol. ii. 
p. 125. 
1856. Petalodus acuminatus, F. McCoy, Brit. Palteoz. Foss. p. 035, 
pi. 3 G. fig. 4. 
(?) 1878. Petalodus hastingsiee, L. G. de Koninck, Faune Ciiic. Carbf. 
Belg. pt. i. p. 60, pi. vi. figs. 0-8. 
