ADDENDA AND ERRATA. 
On page 757 for ‘‘Genus 2. Scolecosoma, Girard ;” read ‘‘Genus 2. Ichthyomyzon. Girard.” 
The proper type of Ichthyomyzon is Petromyzon argenteus Kirtl.; Scolecosoma was based 
on the young of the same species. 
On page 757 for ‘2. Scolecosoma argentewm (Kirtland) Jordan;” read ‘‘ Ichthyomyzon ar- 
genteus (Kirtland) Girard. € 
S % 
On page 764 for “3. Polyodon folium Lacepede;” read “3. Polyodon spathula (Wal- 
baum) Jordan;” and add to the synonymy, ‘‘ Squalus spathula Walbaum, Artedi 
Piscium, 1792, 522.” 
On page 781 for “S11. Anguilla vulgaris Turton ;” read “11. Anguilla rostrata (LeSueur) 
DeKay.” . 
The American Hel seems to be a distinct species from the Common Hel 
of Kurope. The following graphic description of its habits is from the 
pen of Mr. Wm. H. Ballou, of Chicago: 
“They are among the most voracious of carnivorous fishes, They eat most inland 
fishes except the Gar-fish and the Chub. Investigation of six hundred stomachs by 
Oswego fishermen showed that the latter bony fish never had a place on their bill of 
fare. They are particularly fond of game fishes, and show the delicate taste of a con- 
noisseur in their selections from choice Trout, Bass, Pickerel, and Shad. They fear not 
to attack any object when disposed, and their bite on human flesh shows even a vicious 
attitude towards man. On their hunting excursions they overturn huge and small stones 
alike, working for hours if necessary, beneath which they find species of Shrimp and 
Cray fish, of which they are exceedingly fond. Their noses are poked into every imagin- 
able hole in their search for food, to the terror of innumerable small fishes. 
‘‘Hels are to the water what the fish-hawk is to the air. They are among the most 
powerful and rapid of swimmers. Again, they hide in the mud beneath some log or 
overhanging rock, and dart out with tremendous fury on their unsuspecting prey. They 
attack the spawn of other fishes open-mouthed, and are even said to suck the eggs 
from an impaled female. They fearlessly and rapidly dive head foremost in the mud- 
disappearing in aninstant, They are owl-like in their habits, committing their depre- 
dations at night. 
‘No fish is known to feed upon the grown Hel. Pickerel, Gar. fish and Bass are sup- 
posed to devour the young fry.” 
On page 817 for ‘39. Catostomus teres ( Mitchill) LeSueur;” read ‘39. Catostomus com- 
mersonit (Lacepede) Jordan.” 
NotEe.—The present report was prepared by the writer and submitted by him to Pro- 
fessor Newberry in the year 1878. The first part of the report, from page 735 to page 
848, was printed during the summer of 1881, as originally written, the writer’not seeing 
