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EASTMAN : CARBONIFEROUS FISHES FROM THE CENTRAL WEST. 183 
except that the coronal surface is not roughened or vermiculated. The latter 
appearance may be perhaps attributed to varying conditions of wear and pres- 
ervation, and is doubtfully of specific value. 
PHYSONEMUS Aaassiz. 
The mostly small, highly tuberculated Ichthyodorulites known as Physone- 
mus, Erismacanthus, Gampsacanthus, Dipriacanthus, etc., interpreted as lat- 
eral head-spines, may be provisionally referred to the Cochliodontidae. 
Physonemus asper, nom. nov. 
1859. Xystracanthus arcuatus J. Leidy, Proc. Acad. Nat. Sci. Philad., p. 3. 
1873. Xystracanthus arcuatus J. Leidy, Rept. U. S. Geol. Surv. Territ., Vol. I., 
p. 812, Pl. XVIL, Fig. 25. 
1875. Xystracanthus arcuatus St. John and Worthen, Pal. Illinois, Vol. VI., p. 457. 
The type species of Physonemus having been named P. arcuatus by M’Coy 
in 1848, it becomes necessary to designate the type of Leidy’s so-called 
“Xystracanthus” by a new specific title on removing it to Physonemus. 
The name P. asper is accordingly proposed for it in allusion to the coarsely 
tuberculated style of its ornamentation. Jaekel’s theoretical association of 
spines of this character with the teeth of Petalodus and Polyrhizodus, and also 
with the dermal tubercles of Petrodus, has not been proved by any direct 
evidence, and militates with the facts of distribution. 
Formation and Locality. — Missourian ; Leavenworth, Kansas. 
CESTRACIONTIDAE. 
ORODUS Aeassiz. 
Orodus intermedius, sp. nov. 
(Plate 4, Figs. 35, 36.) 
Type. — Detached tooth; Museum of Comparative Zoology. 
Teeth of medium size, upwards of 3cm. in length. Coronal contour grad- 
ually rising into a nearly smooth dome-shaped median eminence ; longitudinal 
crest low, slightly wavy, giving off several groups of branching transverse 
wrinkles extending on either side, and forming slight buttresses on the outer 
coronal margin; base of crown faintly crenulated along the inner margin. 
The unique tooth answering to the above description was obtained by the 
late Mr. Samuel A. Miller from the Upper Coal Measures on the opposite side 
