\ ) ■ 
1018 Wisconsin Academy of Sciences, Arts, and Letters. 
and hoping to find specimens both of bidentata and tridentata; 
to be able to describe them more carefully than had been done 
by Herrick and to discriminate them accurately. Hear Hew 
Orleans I found numerous representatives of the form which 
I readily identified with Herrick’s P. bidentata and which is 
described later. Hothing was found which corresponds to 
P. tridenta, as Herrick calls it. In seeking information 
which should aid me in working up my material, I applied to 
Professor C. Judson Herrick of Denison University, Ohio, 
and through his kindness I received all of the notes and draw¬ 
ings left by his brother, the late Professor C. L. Herrick, re¬ 
garding entomostraca, and also such few specimens as re¬ 
mained of his collection. I have, therefore, all of the original 
notes regarding these species. The specimens were of no 
value. It appears that Professor Herrick was not in the 
habit of keeping a collection of the species which he described 
and all of the entomostraca which had been preserved at 
Denison University were destroyed some years ago in a fire. 
The note-books, however, contain the original sketches from 
which the drawings were made that Herrick gave in the 
original descriptions of P. bidentata and tridentata. The first 
note-book contains numerous sketches of P. bidentata. The 
sketches are not dated and only a few words of description 
are given. It is apparent that they were made from living 
or fresh material during a journey which Herrick took 
through the southern states, probably not later than 1882, 
as species drawn in the note-book are described by him in a 
paper published in 1883. The note-book contains the sketch, 
which forms the basis of plate K, fig. 9, in Herrick’s paper 
of 1884. In the published figure the antennules, the antenna^ 
and postabdomen are put in from the sketches on adjoining 
pages. In the separate drawing of the antennule, which is 
given on this plate, Herrick has unfortunately used one of the 
poorest of the sketches which he made, so that it is plain that 
he never compared his sketches with preserved specimens. In 
a. sketch of the animal seen from the dorsal side Herrick shows 
cue antennule very well, giving the characteristic curve, (See 
PI. LXVII, fig. 2) and also the peculiar form of the base at 
