XI. 
SPECIAL ANATOMY OF THE TERRESTRIAL GASTEROPODA 
OF THE UNITED STATES. By JOSEPH LEIDY, M. D. 
OF PHILADELPHIA. 
INTRODUCTION. 
When the reseai-ches were commenced in the winter 
of 1844, of which the following chapters are the result, it 
was the proposition of Dr. Binney for the author to give 
a complete anatomical anil physiological description of 
the terrestrial Gasteropoda of the United States, includ- 
ing the special and general anatomy, with the embryo- 
logy of the several genera. Before the special anatomy 
was fairly completed, the death of Dr. Binney put a stop 
to the work ; and, a different course of observation hav- 
ing occupied the author's attention, the subject is now 
published, after a long delay, in its present incomplete 
state, from notes taken at the time. 
The animals dissected are as follow : — 
Limax ; L. variegata, L. ajrestis, L. campestris. 
Arion ; A. hortensis. 
Tebennopiiorus ; T. carolinensis. 
Vaginulus ; V. floridanus. 
