Birge—Notes on Cladocera. 
1021 
through the South, employing living or freshly collected ma¬ 
terial. He did not ordinarily employ a camera lucida, nor 
did he take exact measurements. The sketches rarely bear 
date or locality and very few notes, only a word here and there. 
From these sketches he prepared his descriptions and his final 
drawings, which last were often tracings from the sketches. 
He does not seem to have preserved his specimens for study 
at home. At any rate, there are no figures of southern Clado¬ 
cera in his papers of 1884 or 1887 which are not based on the 
sketches of the note-books and the published figures do not 
show any facts that the note-books do not contain. There is 
no evidence that the sketches were corrected by dissections 
made later on preserved material, but there is every reason to 
believe that these field sketches were all he had when writing 
his papers. I believe that the same statement may be made 
regarding the rest of the Crustacea in these papers but I have 
not traced out the originals of all of the very numerous figures. 
So far as I have examined them they are all in the note-books. 
In preparing his paper of 1887 Herrick does not seem to have 
taken the trouble to consult his earlier note-book, as this would 
have shown him at once that he had before him another species 
than his P. bidentata. 
There is some confusion regarding the generic name of P. 
bidentata. In attempting to clear it up a statement of the 
facts is necessary. In 1884 Herrick established the genus 
Pseudosida on specimens found by him at Mobile, Ala. (’84, 
p. 20; PI. K, fig. 9), to which he gave also the specific name 
bidentata. In 1887, as a result of later studies, he changed 
the name of the species to tridentata (’84, p. 3), and ac¬ 
companied the new description with new figures (’87, PL III, 
figs. 2-5). The specific name was erroneously printed e< tri¬ 
dental 3 in this paper. In 1895 Herrick and Turner repeated 
lire last description, including the misprint (’95, p. 147), to¬ 
gether with some remarks from the description of 1884, and 
giving on plates XXXVI and L the figures of the papers of 
1884 and 1887. Ho animals belonging to either species or 
to this genus were seen for more than a decade after 1887. 
In 1898 Haday (’98, p. 64) described P. szalayi, a bidentata 
3—S. & A.—3 
