Occasional Papers of the Museum of Zoology 3 
In considering the various questions involved in the present 
paper, the writers have endeavored to approach each case in 
a judicial manner and under the restrictions imposed by the 
Code. We have attempted to dismiss from our minds every- 
thing that has been written by other writers, and without pre- 
disposition, prejudice or bias, to consider each case solely on 
the merits of the original description. The descriptions of 
Lamarck are to be subjected to the same rules and have been 
accordingly so treated. 
The references given under each form discussed do not rep- 
resent a synonymy, but are intended to furnish a list of those 
places in literature which in each case bear upon the question 
in hand. 
At the inception of the work it was agreed by the authors 
that their conclusions should be submitted to Dr. H. A. Pils- 
bry for his criticism and that in all cases where they were 
unable to agree his decision should be final and accepted by 
the authors. Dr. Pilsbry very kindly consented to act in that 
capacity, and the authors are under great obligations to him 
for his interest in the project and for the large amount of 
time that he has taken in examining the many problems that 
were thus submitted to him. We have adopted his decisions 
in all of the contested cases and have quoted largely from his 
remarks upon others. As now issued, the paper represents 
the unanimous opinion of all three of us on questions of 
nomenclature. 
We are also very much indebted to Dr. C. W. Stiles, of 
Washington, D. C., Secretary of the International Commis- 
sion, for his advice as to the proper interpretation and appli- 
cation of the Code to several cases which arose in the progress 
of the work. 
