No. 428.] PALEOZOIC FISHES. 659 
dental plates in that portion of the mouth. And of these anterior 
teeth I believe we have specimens —a very small, narrow, enrolled 
form — much resembling the ‘second’ tooth of C. contortus. 
“The genus Trigonodus of Newberry will have to be aban- 
doned, it being identical with his Sandalodus. The described 
forms of the latter probably represent the superior dentition. 
| * Very respectfully, 
HO BEF 
[NorE. — It is evident from St. John's pen-and-ink sketch, reproduced 
in Fig. 3, that his specimens of Edestus belong to Æ. minor N. a 
instead of to E. vorax Leidy. The confusion probably arose from the 
fact that Leidy's name is inadvertently applied to the type of E. minor by 
Newberry and Worthen in their explanation of Plate I of the fourth volume 
of the Z7nozs Paleontology, an error which was subsequently corrected. 
The type specimen of E. vorax is now preserved in the Museum of the 
Academy of Natural Sciences of Philadelphia; that of Æ. minor in the 
Cabinet of Amherst College; and that of Æ. giganteus, which is scarcely 
distinct from Æ. vorax, in the Columbia College Museum. The location 
of the type specimen of Æ. heinrichi has been ascertained to be in the State 
University at Urbana, Illinois. 
The depressions on either side of the median projection at a, in Fig. 3, 
are not marks of contact with an adjoining denticl2, as supposed by St. John, 
but are plainly channelings corresponding to the buttressed condition of the 
crown in Campodus variabilis (N. and W.). In fact, a comparison of the 
symphysial series of the latter with the type of Edestus minor proves that 
the coronal apices of the two forms are surprisingly alike. The detached 
segments of Edestus are often pyritiferous, and their decomposition is best 
arrested by treating them with a film of collodion. 
The spccimen of Cochliodus referred to in the second paragraph above 
is figured by St. John and Worthen in Vol. VII of the ///inois Paleon- 
tology, Pl. viii, Fig. 8 a, under the name of Pecilodus sancti-ludovici. 
There seems to be no sufficient reason, however, for its removal from 
Cochliodus. The complete dentition of this genus is known in at least one 
- 
jaws were found in natural iation with the anterior series, the latter 
having the form of “ Helodus” teeth. The symphysial series of the same 
Species has been described by Newberry (Ann. N. Y. Acad. Nat. Sci., 
Vol. xvi, p. 301, Pl. xxiv, Fig. 24) under the name of He/lodus coranus. 
In C. contortus the anterior and symphysial series have not yet been defi- 
nitely recognized as such. ] 
CAMBRIDGE, Mass. 
LI 
