42 
SELACHII. 
The following species have also been founded upon detached 
teeth, but there are no examples in the Collection :— 
Petalorhynchus distortus, St. John & Worthen, Pal. Illinois, vol. vi. 
(1875), p. 406, pi. xii. figs. 7, 8.—Upper St. Louis Lime¬ 
stone; Illinois, Iowa, Missouri. 
Petalorhynchus indicus, W. Waagen, Pal. Ind. ser. 13, pt. i. (1879), 
p. 17, pi. i. fig. 8.—Productus Limestone; Salt Range, 
India. (? Janassa .) 
Petalorhynchus pseudosag ittatus, St. John & Worthen, tom. cit. 
p. 405, pi. xii. figs. 1-4.—Upper St. Louis Limestone; 
Illinois, Iowa, Missouri. 
Petalorhynchus spatulatus , St. John & Worthen, tom. cit. p. 408, 
pi. xii. figs. 5, 6.—Upper St. Louis Limestone; Illinois, 
Iowa. 
Petalorhynchus striatus , Newberry & "Worthen, Pal. Illinois, 
vol. ii. (1866), p. 40, pi. ii. fig. 8.—Burlington Limestone; 
Illinois. 
Genus P£S c X 1 .ALO!DUS 9 Owen. 
[Odontography, 1840-45, p. 61.] 
Syn. Chomatodus , L. Agassiz (in part), Poiss. Foss. vol. iii. 1838, p. 108. 
Antliodus , Newberry & Worthen, Pal. Illinois, vol. ii. 1866, p. 33. 
Sicarius, J. Leidy, Proc. Acad. Nat. Sc-i. Philad. vol. vii. 1856, 
p. 414. ><tk /f cv , c 
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. 
PetalocHrs acuminatus (Agass.). 
1838. Chomatodus acuminatus , L. Agassiz, Poiss. Foss. vol. iii. p. 108, 
pi. 19. figs. 11-13. 
1840-45. Petalodus hastingsii, It. Owen, Odontogr. p. 61, pi. xxii. 
figs. 3-5. 
1843. Petalodus acuminatus , L. Agassiz, tom. cit. pp. 174, 384. 
(P) 1843. Petalodus hastingsii, J. E. Portlock, Rep. Geol. Londonderry, 
p. 468, pi. xiv. fig. 10. 
1848. Petalodus rhombus , F. McCoy, Ann. & Mag. Nat. Hist. [2] vol. ii. 
p. 125. 
1855. Petalodus acuminatus, F. McCoy, Brit. Pakeoz. Foss. p. 635, 
pi. 3 G, fig. 4. 
(?) 1878. Petalodus hastingsice, L. G. de Koninck, Faune Calc. Carbf. 
Belg. pt. i. p. 50, pi. vi. figs. 6-8. 
