208 
SELAcnir. 
Cochliodus latuS) Lcidy. 
1867. CwMiodm kctm, J, Leidy, Trans. Amer. Phil. Sue. [2] vol. xi. 
p. 88, pi. V. fig. 17. 
1800, Helodics {Cochlioditu) nobilis, Newberry & VVortheii, Pal. 
Illinois, vol. ii. p. 89, pi. vii. figs. 1-4, pi. viii. fig. 1. 
1880. Chitonodus lalus, St. John & VVortlien, Pal. Illinois, vol. vii. 
p. 112. 
Type. Portion of “ lower ” dental plate. 
A comparatively largo species, the posterior “ lower ” dental plate 
having an antero-postorior measurement of 0'075. Tho large ridge 
of the posterior “ lower ” plate relatively narrow, with a tendency 
towards angulation, and not quite attaining the inner margin ; 
coronal surface slightly wrinkled at right angles to the inner mar- 
gin. Anterior “lower” dental plate W’ith low ridge and feeble 
plications. Opposing dental plate equal in antero-posterior extent 
to tho two teeth just described, and having the cliaracters of the so- 
called Strehlodus. 
In the lino specimen described by Newberry and Worthen, lor. 
cit., there are several scattered series of i/eZo(?i«s-shai)od teeth in 
association with tho large tt^cth. 
Form. Loc. Keokuk Limestone (Lower Carboniferous) : Illinois, 
U.S.A. 
P. 2430. An almost perfect posterior “ lower ” tooth ; Warsaw. 
Illinois. Ennislcillen Coll. 
'I'lie following species have also boon founded upon detached 
teeth, but there are no examples in the Collection : — 
Cochliodus costatus, Newberry & Worthen, Pal. Illinois, vol. iv. 
(1870), p. 304, pi. iii. figs. 10, 12. — liurlington Lime- 
stone ; Iowa. 
Cochliodus leidyi, 8t. John & Worthen, op. cit. vol. vii. (1883), 
p. 127, pi. vii. figs. 11-16. — Chester Limestone; Illinois. 
[In this species are also included N<re6?ocf«s-likc teeth 
and anterior Ilolodont teeth.] 
Cochliodus tenuis, L. G. do Koninck, Panne Calc. Carbf. Lelg. 
pt. i. (1878), p. 68, pi. vi. fig. 15. — Lower Carboniferous 
Limestone ; Soignios, Tournai. 
Cochliodus van hornii, St. John & Worthen, op. cit. vol. vii. p. 120, 
pi. vii. figs. 1-10. — St. Louis Limestone ; Illinois, Missouri, 
afld Iowa. [Nfrcl>Zo(/Ms-like tooth are hypothetically 
assigned to the upper jaw, and Uelodus-Y\V.Q teeth to the 
more anterior region.] 
