228 
DALL. 
is given or no reference made, were published before Mr. 
Lea’s ‘ Contributions to Geology.’ [Original] No. 3 was 
published August, 1833, and [Say & Morton] No. 4, October, 
1833. They have been reprinted in order to group together 
the species of each genus.” 
The space occupied in the first reprint by the attack on 
Lea is now filled with a paragraph headed “ Corrigenda,” 
which refers to tab. 2, fig. 2, and says of the species there 
represented, “This was described as P[ectunculus]. pulvi- 
natus, but it is now ascertained to be very distinct, and it is 
proposed to name it P. lentiformis,” etc. 
This edition, being less obnoxious to criticism by the 
friends of Mr. Lea, is the one most commonly found in copies 
of the work. The preceding references will enable any one 
to make the correct reference and date for all Conrad’s con¬ 
tested Eocene species and to judge of the disposition which 
should be made of them. 
It may be noted that the plates for this and other works 
of Conrad were drawn and sometimes even put on the stone 
by him, one or two stones being used, and after the edition 
needed had been printed the stone was cleaned off and an¬ 
other drawing made. Mr. Conrad being in modest circum¬ 
stances, could not afford to print large editions, and what 
he published in this way probably never paid for his ex¬ 
penses, which will explain why so few copies were published 
and why it was comparatively easy to suppress the major 
part of the editions printed. 
Several years later Mr. Conrad projected his “ Medial Ter¬ 
tiary ” monograph, also a rare and unfinished work, of which 
it seems as if a collation would be useful to students. 
It appeared in covers, of which the first leaf comprised a 
lithographed title with a figure of Ecphora, drawn by Conrad 
himself, with a blank space intended to be filled by the 
number of the part [written in with a pen], and another for 
the date [also written]. These covers are printed on colored 
paper, brownish, blue, or yellow, and the same cover was 
used for successive parts, only differing by the manuscript 
