PETALODOXTIDJS. 
47 
1872. Petalodus destructor, 0. St. John, Final Rep. U.S. Geol. Surv. 
Nebraska, p. 241, pi. iii. fig. 5. 
1873. Petalodus alleghaniensis, J. Leidy, Extinct Vert. Fauna West. 
Territ. (Rep. U.S. Geol. Surv. Terr it., 1873), p. 312, pi. xvii. fig. 3. 
1875. Petalodus alleghaniensis, J. S. Newberry, Rep. Geol. Surv. Ohio, 
vol. ii. pt. ii. p. 52, pi. lviii. fig. 13. 
Type. Detached tooth. 
Crown of tooth acuminate, much projecting beyond the root an¬ 
teriorly. Lateral margin of the root sharply bent at one third the 
distance from its tapering, but truncate, extremity. 
Torm. df Loc. Coal-Measures: Pennsylvania, Ohio, Arkansas, 
Illinois, Nebraska, U.S.A. . 
E. Trautschold 1 has also recorded this species from the Carboni¬ 
ferous Limestone of Mjatschkowa, near Moscow; but the determi¬ 
nation is extremely doubtful. 
35678. Fine tooth from Turkey Creek, Conway Co., Arkansas. 
Purchased, 1859. 
P. 2981. Crown and portion of root; La Salle, Illinois. 
Enniskillen Coll. 
Some abraded and fragmentary teeth (Nos. P. 4885, 4907, Pur¬ 
chased, 1885) from the Yoredale Rocks of Wensleydale, Yorkshire, 
resemble the fossils described by J. AY. Davis 2 as Glyphanoclus 
tenuis. Upon present evidence, however, these cannot be distin¬ 
guished from worn fragments of Petalodus. 
The following species, referable to Petcdodus as here defined, have 
been founded upon detached teeth, but only three appear to be 
represented in the Collection : these are from the Enniskillen Col¬ 
lection, Nos. P. 2983 (P. parvulus), P. 2980 (A. sulcatus ), and 
P. 2984 (A. politus ) :— 
Petalodus curtus , Newberry & Worthen, Pal. Illinois, vol. iv. 
(1870), p. 355, pi. iii. fig. 2 .—Eeokuk Limestone; Illinois. 
Petalodus hyhridus, St. John & W orthen, Pal. Illinois, vol. vi. 
(1875), p. 394, pi. xii. fig. 10.—St. Louis Limestone; 
Illinois. 
Petalodus knappi , J. S. Newberry, Ann. Rep. Geol. Surv. Indiana, 
1879, p. 345.—Eeokuk Limestone; Indiana. 
Petalodus linguifer, Newberry & Worthen, op. cit. vol. ii. (1866), 
p. 37, pi. ii. figs. 4, 5.—Chester Limestone; Illinois. 
Petalodus “ new variety,” W . J. Parkas, Monthly Rev. Dental 
1 Nouv. Mem. |>oc.Imp.Nat. Moscou, vol.xiv. 1879, p. 56, pi. vii. figs. 13,14. 
2 Trans. Koy. Dublin Soc. [2] toI. i. (1883), p. 386, pi. xlix. figs. 24, 25; and 
Quart. Journ. Geol. Soc. toI. xl. (1884), p. 621, pi. xxyii. fig. 8. 
