374 The American Geologist. December, 1902. 
at the notch between it and the inner lateral cusps, is 4.5mm. 
The lateral outlines are nearly straight to the smooth round- 
ed tip. There is a very gentle' sigmoid flexure. The anterior 
face is rather strongly convex, becoming flattened toward the 
base, and at length somewhat e|xcavated. The lateral edges 
appear to be sharp. The anterior face is occupied by sharp 
costse, about 20 at the base and about 10 just below thei tip. 
The costae near the outer border of the base of the large cusp 
disappear soon in the e^dges of the cusp. The costse all come 
down low on the base of the tooth. 
The lateral cusps are small, conical, and rather slender. 
The inner pair are somewhat the larger. All are ornamented 
with a few sharp costse. 
From Cladodus girtyi Hay, of the Coal-measures of Color- 
ado, this species differs especially in the shorter lateral cusps. 
C. concinnus Newb. of the Cleveland shales of Ohio, has the 
median cusp highel- than the length of the base of the tooth. 
C. intercostatus has on each side of the anterior face a strong 
ridge running parallel with the cutting edge. 
Dr. Eastman has suggested a reteemblance of this new 
species to some varieties of C. springeri, especially with some 
forms of it from Russia. The latter species belongs to the 
Lower Carboniferous, and it is quite unlikely that it will oc- 
cur as low down as the middle Devonian. Most of the speci- 
mens of C. springeri possess several cusps on each side of 
the main cusp, and the base lacJ^s the median sinus. Dr. 
Eastman kindly informs m/e that C. primigenius, of the De- 
vonian of Russia, has also several cusps on each side of the 
main one, and that the latter is slenderer, and the base not 
so sinuate. 
American Museum of Natural History, 
Neiv York, Oct. 10, 1502. 
