A NEW SPECIES OF PETALODUS. 563 
the cutting edge, shows a worn surface, where it has come into 
contact with other teeth. 
Diag Josepheeecichvay@ascthinet Vertebrarem haunayspai3 02, bl 
XVII., Fig. 3) refers P. destructor to his own earlier described P. 
alleghaniensts, and Orestes St. John agrees with the conclusion. 
In case this identity is established the availability of two 
other specific names will have to receive consideration. One of 
them 1s extimctus. This was proposed by Dr. Leidy in 1855 
Groce Ncady Nata. Scr ehilas Volk Vil-ipa4i)pabut: later the 
author essayed to withdraw it in favor of alleghaniensis, But 
there is a still older name which may supersede one or both of 
the names alleghaniensis and destructor. In the Amer. Jour. of 
iG, 2 
SCIENCES, 1953, Series 2, Voll, XOVIL, jo. 142, Jecouessor ||, Wl, Seve 
ford described and gave two wood cuts of a species of Petalodus. 
On this was bestowed the name Gefalodus ohioensis, but the error 
in the generic title is evident. This name and the figure appear 
to have dropped out of sight. Although Professor Safford’s 
specimen lacked the root, the crown was complete and closely 
resembles that of Petalodus destructor. The angles of the tooth 
are, however, rounded off like those of Dr. Leidy’s figure of P. 
alleghaniensis. he size, if we may depend on Professor Safford’s 
drawing, is more nearly that of P. destructor. It is not improbable 
that Professor Safford’s drawings are not wholly accurate and 
this fact may account for the distance of the enamel band from 
the apex on what is evidently intended for the anterior face of 
the tooth. It would be interesting to know whether or not the 
type of Professor Safford’s specimen is yet in existence. In any 
case, the name must be recognized as that of one of our species 
of Petalodus. Should it also result, as is not impossible, that the 
