COCHLIODONTID^. 
199 
Deltodus occidentalis (Leidy). 
1857. Cochliodm occidentalis, J. Leidy, Trans. Araer. Phil, Soc. [21 
vol. xi. p. 88, pi. V. figs. 3-10. 
1866, Deltodus stellntus, Newberry & Worthen, Pal. Illinois, vol. ii. 
p. 97, pi. i.x. figs. 2, 3. 
18.83. Deltodus occidentalis ?, St. John & Worthen, op. dt. vol. vii. 
p. 160, pi. ix. figs. 9, 10. 
Type. Detached dental plates. 
Transverse coronal folds, when present, broad and faintly marked, 
but generally absent. “ Lower ” posterior dental plate "obliquely 
twisted, gently arched, with the outer apex closely inrolled ; 
anterior coronal elevation extending from the outer to the inner 
margin broad, unequally divided by a faint angulation along its 
highest part. 
St. John and Worthen describe the supposed lower median dental 
plate and the upper posterior dental plate of this species. 
Form. ^ Loc. St. Louis, Warsaw, and Keokuk Limestones (Lower 
Carboniferous) : Illinois, U.S.A. 
P. 2453. Two abraded examples ; Keokuk Limestone, Warsaw, 
Illinois. Ennishillen Coll. 
Deltodus spatulatus, Newberry & Worthen. 
1866. Deltodus spatulatus, Newberry & Worthen, Pal. Illinois, vol. ii. 
p. 100, pi. ix. fig. 7. 
1879. Deltodus spahdatus, J. S. Newberry, Ann. Rep. Geol. Surv. 
Indiana, 1876-78, p. 346. 
Type. (?) “ Upper ” dental plates. 
Supposed upper dental plate obliquely spatulate in outline, the 
broader end having rounded angles ; anterior long coronal promi- 
nence gently angulated; nnabraded coronal surface with only faint 
transverse parallel furrows. 
Form. ^ Loc. Burlington and Keokuk Limestones (Lower Car- 
boniferous) : Illinois and Indiana, U.S.A. 
P. 2452. Two imperfect specimens ; Burlington Limestone, Quincy, 
Illinois. Ennishillen Coll. 
The following species have also been founded upon detached 
teeth, but there are no examples in the Collection 
Deltodus alatus, Newberry & Worthen, Pal. Illinois, vol. iv. 
(1870), p. 308, pi. ii. fig. 6. — Keokuk Limestone ; Illinois. 
Deltodus ediformis, J. W. Davis, Trans. Roy. Dublin Soc. [2] 
vol. i. (1883), p. 431, pi. liii. fig. 12 : Fadlodus aliformis. 
