60 
SELACHII. 
Trans. Amer. Phil. Soe. [2] vol. xi. (1857), p. 90, pi. v. 
figs. 27-29.—St. Louis Limestone ; Missouri, Illinois. 
Polyrhizodus longus, H. Trautschold, Nouv. Mem. Soc. Imp. Nat. 
Moscou, vol. xiv. (1879), p. 50, pi. vi. figs. 9, 10.—Carbo¬ 
niferous Limestone ; Mjatschkowa, near Moscow. 
Polyrhizodus ( Dactylodus ) minimus , St. John & Worthen, tom. cit. 
p. 391, pi. xiii. fig. 19.—St. Louis Limestone ; Illinois. 
Polyrhizodus modestus, J. S. Newberry, Pep. Geol. Surv. Ohio, 
vol. ii. pt. ii. (1875), p. 50, pi. Iviii. fig. 10.—Lower- 
Carboniferous; Ohio. 
Polyrhizodus nanus, St. John & Worthen, tom. cit. p. 386, pi. xiii. 
fig. 15.—Keokuk Limestone ; Iowa. 
Polyrhizodus piasaensis, St. John & Worthen, tom. cit. p. 386, 
pi. xiii. fig. 12.—Warsaw Beds; Illinois. 
Polyrhizodus ponticulus , Newberry & Worthen, op. cit. vol. ii. 
p. 51, pi. iii. fig. 11.—Chester Limestone ; Illinois. 
Polyrhizodus porosus, Newberry & Worthen, op. cit. vol. ii. p. 49, 
pi. iii. fig. 9.—Burlington Limestone; Illinois, Iowa. 
Polyrhizodus (Dactylodus) princeps, Newberry & Worthen, op. cit. 
vol. ii. p. 45, pi. iii. fig. 6.—St. Louis Limestone; 
Missouri. 
Polyrhizodus truncatus, Newberry & Worthen, op. cit. vol. iv. 
p. 357, ph iii. fig. 16.—Burlington Limestone; Illinois. 
Polyrhizodus williamsi, St. John & Worthen, tom. cit. p. 384, 
pi. x. a. fig. 23, pi. xiii. fig. 11.—Keokuk Limestone; 
Missouri, Iowa. 
Genus GlaOSSODUS, McCoy, r- m 
[Ann. & Mag. Nat. Hist. [2] vol. ii. 1848, p. 127.] 
Teeth tongue-shaped. Crown very thick, and coronal margin 
obtuse and rounded. Boot long, as wide as the crown, terminating 
below in two points. 
<£“Glossodus lingua-bovis/McCoy^) 
1848. Glossodus lingua-bovis, F. McCoy, Ann. & Mag. Nat. Hist. [2] 
vol. ii. p. 127. 
1848. Glossodus marginatus, F. McCoy, tom. cit. p. 128. 
1855. Glossodus marginatus ,. F. McCoy, Brit. Palaeoz. Foss. p. 629, 
pi. 3 k, fig. 1. 
1883. Glossodus marginatus, J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. p. 510, ph Ixi, figs, 3-5. 
